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Sample records for mayor dc guide

  1. Solar Decathlon Visitors Guide 2011, National Mall, West Potomac Park, Washington, D.C., September 23 - October 2, 2011 (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2011-09-01

    Guide to the student-designed houses, ten contests, exhibits, and workshops of the U.S. Department of Energy 2011 Solar Decathlon, held in Washington, D.C., from September 23 through October 2, 2011. Teams of college students designed and built the solar-powered houses on display here. They represent 13 U.S. states, five countries, and four continents. Now the teams are rising to the challenge by competing in 10 contests over nine days, with the championship trophy on the line. This is their time to shine. The 2011 teams may share a common goal - to design and build the best energy-efficient house powered by the sun - but their strategies are different. One house is made of precast concrete, while another 'dances' in response to its environment. Another house is meant to sit atop a building, proving the sky's the limit for energy innovation. Whatever your idea of sustainable living may be, you are bound to find it at the Solar Decathlon.

  2. Advanced DC/DC converters

    CERN Document Server

    Luo, Fang Lin

    2003-01-01

    DC/DC conversion techniques have undergone rapid development in recent decades. With the pioneering work of these authors, DC/DC converters have now moved into their sixth generation. This book offers a concise, practical presentation of DC/DC converters, summarizing the spectrum of conversion tecnologies and presentingmany new ideas and more than 100 new topologies. Nowhere else in the literature are DC/DC converters so logically sorted and systematically introduced, and nowhere else can readers find detailed information on prototype topologies that represent a major contribution to modern power engineering. More than 320 figures, 60 tables, and 500 formulae facilitate understand and provide precise data.

  3. Redes sociales y mujeres mayores

    OpenAIRE

    Fernández Campomanes, María

    2012-01-01

    Estudio de carácter cualitativo sobre la influencia de las redes sociales en la mejora de la calidad de vida de las mujeres mayores, que responden al perfil de mujeres de más de 55 años de edad, cuidadoras y cuyo acceso a las TIC no guarda relación con el empleo ni con el ámbito académico.

  4. Milliwatt dc/dc Inverter

    Science.gov (United States)

    Mclyman, C. W.

    1983-01-01

    Compact dc/dc inverter uses single integrated-circuit package containing six inverter gates that generate and amplify 100-kHz square-wave switching signal. Square-wave switching inverts 10-volt local power to isolated voltage at another desired level. Relatively high operating frequency reduces size of filter capacitors required, resulting in small package unit.

  5. Maltrato institucional a adultos mayores

    Directory of Open Access Journals (Sweden)

    Miriam Rubio Acuña

    Full Text Available El maltrato institucional se refiere a cualquier forma de abuso que ocurre en servicios dirigidos a los ancianos. Esta revisión bibliográfica muestra que el maltrato se presenta con mayor frecuencia en residencias de larga estadía y el tipo más frecuente es la negligencia. Los factores asociados son los que tienen relación con el residente y con el ambiente. Las principales estrategias son invertir recursos sociosanitarios, sensibilizar a la población respecto al maltrato de los ancianos, considerar las necesidades de estos, fortalecer la formación de pregrado de los profesionales de salud en este ámbito y realizar educación continua. El maltrato es un problema social que debe ser abordado de manera integral.

  6. A Unidirectional DC-DC Autotransformer for DC Grid Application

    Directory of Open Access Journals (Sweden)

    Meng Zhou

    2018-03-01

    Full Text Available Conventional unidirectional DC-DC converters for DC grid application employ DC-AC-DC two-stage conversion technology and suffer from high converter cost and power loss. To solve these issues, a unidirectional step-up DC-DC autotransformer (UUDAT and a unidirectional step-down DC-DC autotransformer (DUDAT are studied. The UUDAT and DUDAT are composed of a series connection of diode bridges and voltage source converters. Topologies of UUDAT and DUDAT are detailed. The harmonic and un-controllability issues are discussed. Control and possible application scenarios for UUDAT and DUDAT are depicted. DC fault isolation mechanism and the methods of dimensioning the voltage and power ratings of the components in UUDAT and DUDAT are studied. Extensive simulations on power system level and experiments on a UUDAT and DUDAT prototype verified their technical feasibility.

  7. Step-Up DC-DC converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam P.; Gorji, Saman A.

    2017-01-01

    on the general law and framework of the development of next-generation step-up dc-dc converters, this paper aims to comprehensively review and classify various step-up dc-dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage...

  8. Abuso y Maltrato en el Adulto Mayor

    OpenAIRE

    Montero Solano, Gustavo; Vega Chaves, Juan Carlos; Hernández, Gabriel

    2017-01-01

    ResumenExiste incongruencia en las definiciones e interpretación del abuso en adultos mayores. Una definición apropiada y unificada es la dada por la Organización Mundial de la Salud, que indica que el abuso en adulto mayor es cualquier acto aislado o repetitivo o la falta de acción apropiada, ocurrida en cualquier relación de la que se espera confianza, que causa daño o malestar a la persona mayor.Este grupo poblacional es particularmente vulnerable, pues es muy probable que, en algún moment...

  9. The Mayor's Influence in Urban School Desegregation

    Science.gov (United States)

    Dunaway, David King; Beckum, Leonard Charles

    1977-01-01

    There are five primary areas in which mayors exert visible and invisible influence--appointments, decision-making, public statements, coordination of resources, and provision of basic services. (Author/IRT)

  10. Dr Stanislaw Huskowski, Mayor of Wroclaw, Poland

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    Dr Stanislaw Huskowski, Mayor of Wroclaw, Poland visiting the ATLAS magnet assembly hall, building 180. From l to r: Mr Carlo Lamprecht, State Councillor, Dr Stanislaw Huskowski and Dr Peter Jenni, ATLAS Spokesperson

  11. Dr Stanislaw Huskowski, Mayor of Wroclaw, Poland

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    Dr Stanislaw Huskowski, Mayor of Wroclaw, Poland visiting the ATLAS magnet assembly hall, building 180 with Mr Carlo Lamprecht, State Councillor, Dr Stanislaw Huskowski and Dr Peter Jenni, ATLAS Spokesperson

  12. Isolated step-down DC -DC converter for electric vehicles

    Science.gov (United States)

    Kukovinets, O. V.; Sidorov, K. M.; Yutt, V. E.

    2018-02-01

    Modern motor-vehicle industrial sector is moving rapidly now towards the electricity-driving cars production, improving their range and efficiency of components, and in particular the step-down DC/DC converter to supply the onboard circuit 12/24V of electric vehicle from the high-voltage battery. The purpose of this article - to identify the best circuitry topology to design an advanced step-down DC/DC converters with the smallest mass, volume, highest efficiency and power. And this will have a positive effect on driving distance of electric vehicle (EV). On the basis of computational research of existing and implemented circuit topologies of step-down DC/DC converters (serial resonant converter, full bridge with phase-shifting converter, LLC resonant converter) a comprehensive analysis was carried out on the following characteristics: specific volume, specific weight, power, efficiency. The data obtained was the basis for the best technical option - LLC resonant converter. The results can serve as a guide material in the process of components design of the traction equipment for electric vehicles, providing for the best technical solutions in the design and manufacturing of converting equipment, self-contained power supply systems and advanced driver assistance systems.

  13. DC Home Appliances for DC Distribution System

    Directory of Open Access Journals (Sweden)

    MUHAMMAD KAMRAN

    2017-10-01

    Full Text Available This paper strengthens the idea of DC distribution system for DC microgrid consisting of a building of 50 apartments. Since the war of currents AC system has been dominant because of the paucity of research in the protection of the DC system. Now with the advance research in power electronics material and components, generation of electricity is inherently DC as by solar PV, fuel cell and thermoelectric generator that eliminates the rectification process. Transformers are replaced by the power electronics buck-boost converters. DC circuit breakers have solved the protection problems for both DC transmission and distribution system. In this paper 308V DC microgrid is proposed and home appliances (DC internal are modified to operate on 48V DC from DC distribution line. Instead of using universal and induction motors in rotary appliances, BLDC (Brushless DC motors are proposed that are highly efficient with minimum electro-mechanical and no commutation losses. Proposed DC system reduces the power conversion stages, hence diminishes the associated power losses and standby losses that boost the overall system efficiency. So in view of all this a conventional AC system can be replaced by a DC system that has many advantages by cost as well as by performance

  14. Diabetes mellitus en adultos mayores costarricenses

    Directory of Open Access Journals (Sweden)

    Rosero-Bixby, Luis

    2007-07-01

    Full Text Available El propósito del artículo es describir la prevalencia de la diabetes mellitus (DM entre los adultos mayores costarricenses. Se analiza la magnitud de la prevalencia, los problemas de medición de la misma, así como los factores asociados con la enfermedad, la enfermedad controlada, y el tener niveles altos de hemoglobina glicosilada (HbA1C entre la población sin diagnóstico previo de DM. Una cuarta parte de los adultos mayores de Costa Rica padecen de DM y cerca de la mitad de los que la padecen, no la tienen controlada. Los factores asociados con la prevalencia de la enfermedad son los usuales destacados por la literatura científica: actividad física, obesidad e historia familiar de DM. Se halla evidencia de un posible problema de acceso diferencial a servicios de control de DM, ya que los adultos mayores que habitan fuera de la gran área metropolitana de San José tienen un riesgo menor de tener controlada su enfermedad. Los adultos mayores sin pensión también tienen un riesgo mayor de tener niveles altos de HbA1C.

  15. Diabetes mellitus en adultos mayores costarricenses

    Directory of Open Access Journals (Sweden)

    Gilbert Brenes-Camacho

    2007-01-01

    Full Text Available El propósito del artículo es describir la prevalencia de la diabetes mellitus (DM entre los adultos mayores costarricenses. Se analiza la magnitud de la prevalencia, los problemas de medición de la misma, así como los factores asociados con la enfermedad, la enfermedad controlada, y el tener niveles altos de hemoglobina glicosilada (HbA1C entre la población sin diagnóstico previo de DM. Una cuarta parte de los adultos mayores de Costa Rica padecen de DM y cerca de la mitad de los que la padecen, no la tienen controlada. Los factores asociados con la prevalencia de la enfermedad son los usuales destacados por la literatura científica: actividad física, obesidad e historia familiar de DM. Se halla evidencia de un posible problema de acceso diferencial a servicios de control de DM, ya que los adultos mayores que habitan fuera de la gran área metropolitana de San José tienen un riesgo menor de tener controlada su enfermedad. Los adultos mayores sin pensión también tienen un riesgo mayor de tener niveles altos de HbA1C.

  16. Numerical simulation of dynamics of brushless dc motors for aerospace and other applications. Volume 2: User's guide to computer EMA model

    Science.gov (United States)

    Demerdash, N. A. O.; Nehl, T. W.

    1979-01-01

    A description and user's guide of the computer program developed to simulate the dynamics of an electromechanical actuator for aerospace applications are presented. The effects of the stator phase currents on the permanent magnets of the rotor are examined. The voltage and current waveforms present in the power conditioner network during the motoring, regenerative braking, and plugging modes of operation are presented and discussed.

  17. Step-Up DC-DC converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam P.; Gorji, Saman A.

    2017-01-01

    on the general law and framework of the development of next-generation step-up dc-dc converters, this paper aims to comprehensively review and classify various step-up dc-dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage......DC-DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts to megawatts. The literature has reported on various voltage-boosting techniques, in which......-boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc-dc converters are presented and summarized with comparative study of different voltage-boosting techniques....

  18. DC electric springs with DC/DC converters

    DEFF Research Database (Denmark)

    Wang, Qingsong; Cheng, Ming; Jiang, Yunlei

    2016-01-01

    The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi-directio......The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi...... and/or constant discharging for batteries is adopted and four operating modes are analyzed as charging-positive, charging-negative, discharging-positive and discharging-negative modes. An additional mechanism for fast charging or fast discharging is also designed to secure normal operation...... of batteries. With the proposed DCES, the power fluctuations due to intermittent RESs can be passed to non-critical loads (NCLs) and batteries while power on critical loads (CLs) is kept stable. This is possibly the first attempt to design a DCES with only DC/DC converters. The performances of the proposed...

  19. Subjetividad urbana de los adultos mayores

    OpenAIRE

    Rinaldi, Nicolás Darío

    2008-01-01

    El objetivo general de la investigación consiste en vislumbrar características psicológicas de la subjetividad de los mayores, indagando sobre las modalidades de participación social e interacción subjetiva, con el propósito de reconocer las actividades de vinculación como generadoras de salud psíquica. Nos propusimos echar luz sobre los procesos de elaboración propios de la población mayor, atendiendo a sus representaciones sobre el proceso de envejecimiento, y a las motivaciones y...

  20. Calidad de vida en las personas mayores

    OpenAIRE

    Sanduvete Chaves, Susana

    2004-01-01

    El concepto “calidad de vida” adopta una especial relevancia cuando de personas mayores se trata debido a que, a veces, los servicios que reciben están limitados a nivel asistencial, cubriendo sólo las necesidades básicas en lugar de considerar a la persona como un ser integral. Este trabajo pretende ahondar en esta cuestión. Se realizó un estudio bibliométrico para determinar las características de los programas de atención a personas mayores en la actualidad, especificando puntos débi...

  1. Enfermedades endocrinas en el adulto mayor

    Directory of Open Access Journals (Sweden)

    B. Carlos García, Dr.

    2013-09-01

    A pesar de la heterogeneidad, múltiple co morbilidad y escasa literatura en que se incluye adultos mayores, se proponen algunas recomendaciones para el tratamiento individual del paciente diabético anciano, se revisan las particularidades del diagnóstico y tratamiento del híper e hipotiroidismo, algunas ideas en relación al manejo de la osteoporosis en la mujer mayor y el hombre anciano. Finalmente se aborda la dificultad diagnóstica del hipogonadismo tardío con las indicaciones y contra indicaciones del uso de testosterona.

  2. Maltrato en el adulto mayor institucionalizado

    OpenAIRE

    Eu. Yuly Adams, C.

    2012-01-01

    El maltrato al adulto mayor es un fenómeno presente tanto en nuestro país como en el extranjero, del que no existen estadísticas claras y actualizadas que permitan evaluar su impacto personal ni social. No obstante, en Chile, en el actual escenario de transición demográfica, se presume su protagonismo. En los establecimientos de larga estadía para adultos mayores, el maltrato, es una situación real y recurrente. Si bien en este ámbito específico las estadísticas son aun más escasas, los me...

  3. Templo Mayor, Tenochtitlan - Calendar and Astronomy

    Science.gov (United States)

    Galindo Trejo, Jesús

    The Templo Mayor of Tenochtitlan was the principal symbol of political power and religious control of the Mexicas. Its orientation was chosen according to ancestral calendrical traditions that considered the Mesoamerican calendar as a sacred concern. The solar alignments incorporated into this emblematic building symbolized moments that divided the solar year according to basic properties of the Mesoamerican calendar.

  4. A resonant dc-dc power converter assembly

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the s......The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor...... of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or forcing substantially 0 degree phase shift, between corresponding resonant voltage waveforms of the first...

  5. IGBT Based DC/DC Converter

    Directory of Open Access Journals (Sweden)

    M. Akherraz

    1997-12-01

    Full Text Available This paper presents an in-depth analytical and experimental investigation of an indirect DC-DC converter. The DC-AC conversion is a full bridge based on IGBT power modules, and the AC-DC conversion is done via a high  frequency AC link and a first diode bridge. The AC link, which consists of snubbing capacitors and a variable air-gap transformer, is analytically designed to fulfill Zero Voltage commutation requirement. The proposed converter is simulated using PSPICE and a prototype is designed built and tested in the laboratory. PSPICE simulation and experimental results are presented and compared.

  6. A resonant dc-dc power converter assembly

    OpenAIRE

    Madsen, Mickey Pierre

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or fo...

  7. Cirugía bucal mayor ambulatoria

    OpenAIRE

    Carranza Pelegrina, Daniela; Bellorbí Malet, I.; Brescó Salinas, Vicente Miguel; Berini Aytés, Leonardo; Gay Escoda, Cosme

    2004-01-01

    La Cirugía Bucal Mayor Ambulatoria ( CBMA) se define como un modelo organizativo óptimo de asis­tencia quirúrgica multidisci­plinaria que permite tratar a determinados pacientes de una forma segura y efectiva sin necesidad de contar con la cama de hospitalización tradicional. De esta manera se llevan a cabo distintos procedimientos diagnósticos y terapéuticos de mediana complejidad en los que el enfermo regresa a su domici­lio después de un periodo de observación y control. Entre las ventajas...

  8. Diabetes Mellitus en el adulto mayor

    OpenAIRE

    Guerrero-Godínez, Juan; Barragán-Vigil, Ana; Navarro-Macias, Carmen; Murillo-Bonilla, Luis; Uribe-González, Paul; Sánchez-Cruz, Martha

    2017-01-01

    La Diabetes Mellitus, una enfermedad crónica que afecta a todo el mundo siendo nuestro país México, el primer lugar con esta enfermedad, su incidencia aumenta junto con la edad hasta un 20% en personas mayores de 60 años todos ellos susceptibles a síndromes geriátricos, con posibles repercusiones ya sea por falta de control de niveles de glicemia o por un exceso en el control. El objetivo de esta revisión no sistemática es concientizar a la población general de la diabetes mellitus y el conte...

  9. EL SINDROME VESTIBULAR EN EL ADULTO MAYOR

    Directory of Open Access Journals (Sweden)

    Dr. Hamlet Suárez

    2016-11-01

    Full Text Available El vértigo, la inestabilidad y las caídas tienen una incidencia relevante en el adulto mayor, disminuye su calidad de vida y puede ser causa de muerte en esta población. Este artículo describe las presentaciones clínicas y el abordaje de la evaluación de la patología vestibular en este grupo de edad, utilizando diferentes instrumentos para el diagnóstico así como también las reglas generales del tratamiento.

  10. Incontinencia urinaria en el adulto mayor

    Directory of Open Access Journals (Sweden)

    Humberto Chiang, Dr.

    2018-03-01

    Full Text Available Resumen: La incontinencia urinaria (IU es una condición prevalente en la población de adultos mayores, afectando a ambos sexos. Con el envejecimiento de la población será un problema de salud de cada vez mayor relevancia. Su patogenia es compleja y multifactorial, por lo que es fundamental conocer los aspectos fisiopatológicos subyacentes para realizar un adecuado diagnóstico en base a la historia clínica, examen físico y exámenes complementarios solicitados de manera racional. El tratamiento de la IU para adultos mayores no difiere mayormente de los tratamientos utilizados en población más joven. Sin embargo, debe hacerse particular énfasis en identificar comorbilidades, fármacos, trastornos neurológicos y psiquiátricos que puedan estar contribuyendo a la IU. Debe sacarse el máximo provecho del manejo conservador, teniendo consideraciones especiales con el uso de algunos fármacos e indicando cuidadosamente tratamiento quirúrgico a pacientes seleccionados. Summary: Urinary incontinence (UI is a prevalent condition in the population of elderly adults, affecting both sexes. With the aging of the population it will be a health problem of increasing relevance. Its pathogenesis is complex and multifactorial, so it is essential to know the underlying pathophysiological aspects in order to make an adequate diagnosis based on the clinical history, physical examination and complementary tests requested in a rational manner. The treatment of UI for elderly adults does not differ much from the treatment of younger population. However, particular emphasis should be placed on identifying comorbidities, medications, neurological and psychiatric disorders that may be contributing to the UI. Full advantange of conservative management should be taken, having special considerations with the use of some drugs and carefully indicating surgical treatment to selected patients. Palabras clave: Incontinencia urinaria, adulto mayor, envejecimiento

  11. Los derechos de las personas mayores

    Directory of Open Access Journals (Sweden)

    Francisco Javier Leturia Arrazola

    2011-12-01

    Full Text Available Este trabajo pretende reflejar el modelo y metodología de inclusión de la perspectiva de los derechos en el modelo de intervención psicosocial orientado a la calidad de vida (Shalock y Verdugo 2006 de las personas mayores, aplicado por los autores y sus equipos en los últimos años, especialmente en Matia Fundazioa, y su utilidad como estrategia preferente de prevención del trato inadecuado. Ha sido becado y publicado por el Defensor del Pueblo del País Vasco, “Ararteko” (2008 en el libro: “Los derechos de las personas mayores y la prevención del mal trato” This work tries to reflect the model and methodology for mainstreaming of rights in the psychosocial intervention model aimed at the quality of life (Shalock and Verdugo, 2006 of the elderly operated by the authors and their teams in recent years Matia Foundation and especially its usefulness as a preferred strategy for the prevention of improper treatment. It was granted and published by the Basque Country Ombudsman “Ararteko” (2008 on the book: “The rights of the elderly and prevention of ill treatment”Download this paper from SSRN: http://ssrn.com/abstract=1963683

  12. Welcome by the Mayor of Valtetsi

    Science.gov (United States)

    Papanikolau, N.

    Welcome by the Mayor of Valtetsi Mr. Chairman Ladies and Gentlemen The municipality of Valtetsi welcomes you and wishes success in your work. Arcadia is both a historical and modern region. Moreover, as a name it remained in the western culture recalling a harmonious and peaceful dream, a lost and desirable situation where the human being lived in balance with nature, a region where the person did not feel yet uprooted. For thousands of years the poetic voices retained vivid this eternal bucolic call of simplicity and accessible happiness. Gazing the starlit sky we will always see Kallisto, the daughter of Lykaona, king of Arcadia and her son Arcadian as they were both transformed in to the constellations Major and Minor Ursus because of the erotic libido of Jupiter and the jealousy of Hera. And we will always remember Centaurus Cheirona, the great schoolteacher of ancient heroes, who was the first to name the constellations according to mythology. Finally we would like to thank the patriot Mr. T. Tzioumi who returns to his beautiful village in Arcadia just like Antaios did. In the geographic place that inspired the arcadian ideal, such activities recall in the limelight Arcadia as was dreamed by Europe. Mr. Chairman, ladies and gentlemen, success in your scientific work. The Municipality of Valtetsi and I myself will be always next to you so that your stay at Arcadia will always remain vivid in your memory. Thank you. Nikos Papanikolaou Mayor of Valtetsi

  13. Un estudio exploratorio de capacidades emocionales en adultos mayores

    Directory of Open Access Journals (Sweden)

    Zoe S. Bello Dávila

    2012-01-01

    Full Text Available Abstract The study of the emotional world of the elderly is a fundamental requisite for guaranteeing the well-being and health of this group. The objective of this research paper was to characterize a group of elderly people according to their motional capabilities. The group consisted of 122 elderly persons: 107 female, 15 male. All attendants participated in a “Círculo de Abuelos” (Circle of Grandparents. The study was descriptive, it sought to gather information about the responses of older adults in situations of emotional content by completing a questionnaire. The results provided a profile of capacities where areas of strength and weakness are clearly distinguished. Selfconfidence and the possibility of fulfilling projects are among the strengths while the weaknesses are found in interpersonal or intrapersonal managing of emotions. These results have led to a better understanding of the emotional world of the elderly and guide future educational activities. Resumen El estudio del mundo emocional de los adultos mayores es un requisito fundamental para garantizar el estado de bienestar y salud de los mismos. El presente artículo de investigación se fijó como objetivo caracterizar a un grupo de ancianos, en función de sus capacidades emocionales. Los participantes fueron 122 ancianos, en concreto 107 mujeres y 15 hombres, que asisten a un “Círculo de Abuelos”. El estudio fue de tipo descriptivo, pues pretendió recoger información acerca de las respuestas de los adultos mayores ante situaciones de contenido emocional que se exploran por medio de un cuestionario elaborado al efecto. Los resultados ofrecen un perfil de capacidades en que la autoconfianza y la posibilidad de elaborar proyectos se erigen como fortalezas, mientras que las debilidades se expresan en las dificultades para el manejo emocional tanto a nivel intra como interpersonal. Estos resultados han permitido lograr una mejor comprensión del mundo emocional del

  14. Full range ZVS DC-DC converter

    International Nuclear Information System (INIS)

    Upadhyay, Rinki; Badapanda, M.K.; Hannurkar, P.R.

    2011-01-01

    A 500 V, 24 Amp DC-DC converter with digital signal processor (DSP) based control and protection has been designed, fabricated and tested. Its power circuit consists of IGBT based single phase inverter bridge, ferrite transformer and diode rectifier. All IGBTs in the inverter bridge are operated in zero voltage switching (ZVS) mode to minimize switching losses thereby increasing the efficiency of the converter significantly. The efficiency of this converter is measured to be greater than 97% at full load. In a conventional full bridge inverter, typically ZVS is achieved under full load condition while at light load ZVS is lost. An auxiliary LC circuit has been intentionally incorporated in this converter to achieve ZVS even at light loaded conditions. Detailed simulation of the converter circuit is carried out and crucial waveforms have been presented in this paper. Microchip make dsPIC30F2020 DSP is employed to provide phase shifted PWMs to IGBTs in the inverter bridge. All the crucial parameters are also monitored by this DSP and in case of any unfavorable conditions, the converter is tripped off. Suitable experiments were carried out in this DC-DC converter under different loaded conditions and a close match between the simulated and experimental results were obtained. Such DC-DC converters can be connected in series or parallel for the development of solid state modular power supplies for various applications. (author)

  15. Morbilidad cardiovascular en el adulto mayor

    Directory of Open Access Journals (Sweden)

    Rita Campillo Motilva

    2001-12-01

    Full Text Available Se realizó un estudio transversal y descriptivo, con el objetivo de definir la morbilidad por enfermedad cardiovascular en pacientes de 60 años y más, en un consultorio médico perteneciente al Policlínico Docente "Dr. Mario Escalona Reguera" del municipio Habana del Este, en el período entre marzo y diciembre del año 2000. Fueron incluidos 69 pacientes, 52 de los cuales (75,3 % presentó algún tipo de enfermedad cardiovascular, y fue el sexo femenino el más afectado (51,9 %. La enfermedad que se encontró con mayor frecuencia fue la hipertensión arterial (43 pacientes para un 62,3 %, observamos que la sistodiastólica (86,1 % y el estadio II (53,5 % fue donde se incluyeron mayor número de individuos. Otras enfermedades encontradas fueron los trastornos electrocardiográficos (33 pacientes para un 47,8 % y valvulopatías (18 pacientes para un 26 %.A cross-sectional and descriptive study was conducted in order to define morbidity due to cardiovascular disease in patients aged 60 and over in a family physician’s office of "Dr. Mario Escalona Reguera" Teaching Polyclinic, in Habana del Este municipality, from March to December, 2000. 69 patients were included. 52 of them (75.3 % had some type of cardiovascular disease and females were the most affected (51.9 %. Arterial hypertension was the most commonly found disease (43 patients for 62.3 %. Most of the individuals were included in the systodiastolic (86.1 % and in stage II (53.5 %. Electrocardiographic disorders (33 patients for 47.8 % and valvulopathies (18 patients for 26 % were other of the diseases detected.

  16. High voltage dc cables

    Energy Technology Data Exchange (ETDEWEB)

    Bjustrom, B

    1965-12-01

    How stress distribution in dc cables varies with temperature and stress level, influence of polarity reversals and space charges, and different types of overvoltage to which dc cable may be subjected are discussed. Design problems, especially as related to corrosion protection and to mechanical stress caused by wire armoring during manufacturing and laying, accessories and work done on test methods, and the possibility of designing 400 to 600 kV dc cables for transmitting 2000 to 4000 MW are described.

  17. Family of multiport bidirectional DC-DC converters

    NARCIS (Netherlands)

    Tao, H.; Kotsopoulos, A.; Duarte, J.L.; Hendrix, M.A.M.

    2006-01-01

    Multiport DC-DC converters are of potential interest in applications such as generation systems utilising multiple sustainable energy sources. A family of multiport bidirectional DC-DC converters derived from a general topology is presented. The topology shows a combination of DC-link and magnetic

  18. Salud mental en el adulto mayor: trastornos neurocognitivos mayores, afectivos y del sueño

    Directory of Open Access Journals (Sweden)

    Tania Tello-Rodríguez

    Full Text Available RESUMEN Existen numerosos factores biológicos, psicológicos y sociales con impacto más o menos prominente en la salud mental de las personas adultas mayores. Aparte de componentes derivados de los procesos normales de envejecimiento o de la coocurrencia de enfermedades médicas diversas, eventos como la muerte de un ser querido, la jubilación o la discapacidad, contribuyen significativamente a una variedad de problemas mentales o emocionales en esta fase del ciclo vital. Los problemas más frecuentes afectan las esferas neurocognitiva, afectiva y onírica. Los trastornos neurocognitivos mayores reducen el rendimiento general del paciente y generan con ello exigentes necesidades de dependencia y cuidado cercano. Los trastornos afectivos pueden acentuarse por falta de apoyo familiar y disminución marcada de interacciones sociales que pueden dar lugar a un significativo aislamiento con conducta suicida resultante. La mayor frecuencia de trastornos del sueño como insomnio, somnolencia diurna y trastornos específicos como apnea obstructiva alteran significativamente la calidad de vida de esta población.

  19. El Maestro Universitario: Un Mayor de Edad

    Directory of Open Access Journals (Sweden)

    Néstor Alonso Sánchez Cardozo

    2015-10-01

    Full Text Available Este artículo analiza los cambios asociados a la adquisición de la “mayoría de edad” por parte del docente universitario. En tal sentido, diversos estudios desarrollados en los últimos tiempos le permiten al autor afirmar tal enunciado. En efecto, la reflexión plantea la existencia de rupturas epistemológicas frente al paradigma tradicional de formación del docente, lo que nos lleva a reposicionar su conceptualización como un proceso de construcción social, que se reconstruye a partir de las políticas implementadas para el desarrollo de la universidad.  SummaryThis article analyzes the changes associated to the acquisition of “adulthood” by part of university teachers. In such sense, diverse studies developed lately allow the author to affirm such statement. In fact, this reflection states the existence of epistemological breaks facing the traditional paradigm of teacher training. This make us redefine its conceptualization as a process of social construction, which is rebuilt from the policies implemented for the university development.

  20. Arctic oil exploration Former mayor says yes

    Energy Technology Data Exchange (ETDEWEB)

    Kaleak, J. Sr.

    Alaska's coastal plain can sustain both wilderness values and oil production, says Jeslie Kaleak, Sr., former mayor of North Slope Borough in Borrow, Alaska. Kaleak is director is Barrow Operations for North Slope Regional Corporation. Nevertheless, Kaleak contends, [open quotes]the people in the Lower 48 want to keep us from developing this land because of some preconceived notion of the land as a wilderness paradise.[close quotes] Kaleak insists that the Inupiaq people, American Indians inhabiting the Northern Slope region, have provided for their families for thousands of years by turning to the natural environment. Their decision to support oil development is no different. Kaleak contends that the mineral and oil wealth of the North Slope has allowed the Inupiaq people to improve their standard of living drastically. Oil development on the coastal plain, Kaleak contends, could provide similar economic benefits. [open quotes]We cannot define our lives by the vision of distant people who view the North Slope as one great outdoor Disneyland where...all resources remain off limits to us,[close quotes] Kaleak concludes.

  1. Eritema multiforme mayor desencadenado por antimicrobianos

    Directory of Open Access Journals (Sweden)

    Ronaldo de Carvalho Raimundo

    2010-03-01

    Full Text Available El eritema multiforme, aparece como una enfermedad sistémica con la participación de la piel y las membranas mucosas en relación con varios factores como las infecciones bacterianas o virales, y en particular la administración de drogas, analgésicos y antibióticos en general. Se presenta un paciente masculino de 29 años de edad con eritema multiforme mayor desencadenado por antimicrobianos con la aparición de lesiones vesiculares-bulloso-ulcerosas en las regiones de los labios, encías, la lengua y la mucosa genital en tratamiento de una infección del tracto urinario con norfloxacino 400 mg por una semana. Fue realizado un tratamiento de soporte con el uso de colutorios para la higienización bucal y pomada a base de corticoide para protección de las úlceras, antihistamínicos y orientación nutricional de dieta líquida hipercalórica e hiperproteica. Este síndrome está caracterizado como un proceso eruptivo buloso agudo que compromete la calidad de vida del paciente y no hay pruebas de laboratorio específicas por lo que su diagnóstico debe estar basado en la revisión minuciosa de la anamnesis y en los hallazgos clínicos.

  2. Programmable dc motor controller

    Science.gov (United States)

    Hopwood, J. E.

    1982-11-01

    A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.

  3. Tumores de glándulas salivales mayores

    OpenAIRE

    Martin Berdasco, Franscisco; Meleg de Smith, Suzanne

    2011-01-01

    Se estudiaron 174 tumores de las glándulas salivales mayores recogidos de los archivos del Departamento de Patología del Instituto Nacional de Cancerologia en un período de 15 años (1954-1968). Hasta donde sabemos, esta serie representa el número mayor de casos de tumores de glándulas salivales mayores publicado en nuestro medio.

  4. Multilevel DC link inverter

    Science.gov (United States)

    Su, Gui-Jia

    2003-06-10

    A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.

  5. Political Leadership in Issue Networks : How Mayors Rule Their World?

    NARCIS (Netherlands)

    Denters, Sebastianus A.H.; Steyvers, Kristof; Klok, Pieter-Jan; Cermak, Daniel; Heinelt, Hubert; Magnier, Annick; Cabria, Marcello; Reynaert, Herwig

    2018-01-01

    In his controversial book If Mayors Ruled the World, US political theorist Benjamin Barber argued that mayors can and do play a major role in solving today’s grand societal challenges in domains like social inclusion and poverty, climate change and sustainability and safety and public order. It is

  6. Bidirectional dc-to-dc Power Converter

    Science.gov (United States)

    Griesbach, C. R.

    1986-01-01

    Solid-state, series-resonant converter uses high-voltage thyristors. Converter used either to convert high-voltage, low-current dc power to lowvoltage, high current power or reverse. Taking advantage of newly-available high-voltage thyristors to provide better reliability and efficiency than traditional converters that use vacuum tubes as power switches. New converter essentially maintenance free and provides greatly increased mean time between failures. Attractive in industrial applications whether or not bidirectional capability is required.

  7. ¿Las personas mayores son testigos fiables?

    Directory of Open Access Journals (Sweden)

    Alaitz Aizpurua

    2011-07-01

    Full Text Available Imaginemos que en un juicio llaman a declarar como víctima o testigo a una persona mayor, situación cada vez más probable debido al envejecimiento de la población. En este artículo analizamos las diferencias entre jóvenes y mayores en la exactitud y fiabilidad del testimonio. Los mayores recuerdan con precisión aspectos representativos o la esencia del acontecimiento, pero recuerdan peor que los jóvenes detalles específicos. En pruebas de reconocimiento que requieren discriminar o verificar los hechos, las personas mayores tienen más falsas memorias y las experimentan como recuerdos verídicos en mayor medida que los jóvenes, produciendo así testimonios menos fiables.

  8. A DC Transformer

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of the project was to demonstrate a true direct current (DC) transformer, a new electro-mechanical component with potentially high power applications; in...

  9. Three new DC-to-DC Single-Switch Converters

    Directory of Open Access Journals (Sweden)

    Barry W. Williams

    2017-06-01

    Full Text Available This paper presents a new family of three previously unidentified dc-to-dc converters, buck, boost, and buck-boost voltage-transfer-function topologies, which offer advantageous transformer coupling features and low capacitor dc voltage stressing. The three single-switch, single-diode, converters offer the same features as basic dc-to-dc converters, such as the buck function with continuous output current and the boost function with continuous input current. Converter time-domain simulations and experimental results (including transformer coupling support and extol the dc-to-dc converter concepts and analysis presented.

  10. Basic Design Report of DC-TOF Inelastic Neutron Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    So, Ji Yong; Park, Je Geun; Moon, Myung Kook; Cho, Sang Jin; Choi, Yung Hyun; Lee, Chang Hee

    2006-04-15

    We made Basic designs of neutron guide, choppers, and detectors in order to optimize the design parameters of DC-TOF to be built in the HANARO Cold Neutron Guide Hall. In addition, we calculated the expected performance of DC-TOF using Monte Carlo simulations and evaluated the properties of neutron beam. Based on the results we obtained, we have compared the expected performance of the DC-TOF with those of existing instruments overseas. In conclusion, we believe that we will be able to construct the DC-TOF at HANARO as one of the best instruments of its kinds and it will become an invaluable instrument to researchers in the related field.

  11. Factores asociados al maltrato del adulto mayor de Antioquia, 2012

    OpenAIRE

    Sara M. Cano; María O. Garzón; Ángela M. Segura; Doris Cardona

    2015-01-01

    Objetivo: determinar los factores asociados al maltrato del adulto mayor del departamento de Antioquia en el año 2012. Metodología: mediante estudio descriptivo transversal, se caracterizaron los factores demográficos, económicos y de salud mental de la población adulta mayor de Antioquia para el año 2012, con el fin de aportar al análisis de la situación de salud y condiciones de vida del adulto mayor. El estudio se basó en los resultados del instrumento aplicado por la Universidad ces a 4.2...

  12. Three-port DC-DC converter with new integrated transformer for DC Distribution Systems

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2014-01-01

    A new integrated transformer for three-port dc-dc converter is proposed to overcome the power coupling effect existed in some known multiple inputs dc-dc converters. Orthogonal primary windings arrangement and in series connection of diagonal secondary Windings enables a fully power decoupling...

  13. 75 FR 23571 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-05-04

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10... amends Sec. 39.13 by adding the following new AD: 2010-09-12 McDonnell Douglas Corporation: Amendment 39... to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A...

  14. Design and Testing of Boost Type DC/DC Converter for DC Motor Control Applications

    OpenAIRE

    Samman, Faizal Arya; Akil, Yusri Syam; Noor, Nirwan A.

    2017-01-01

    in The Proceeding of The 2nd International Symposium on Smart Material and Mechatronics 2015 This paper presents the design and testing of a boost type DC/DC converter circuit, which can be used for DC motor control applications. The Boost converter is designed using DC chopper and DC chopper cascade configurations. The experimental setup was made by connecting the boost converter circuit with four types of DC motor, i.e. self-excited DC motor shunt, series, compound and separately exci...

  15. Control of improved full-bridge three-level DC/DC converter for wind turbines in a DC grid

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter......This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency...

  16. Black Perceptions of the Mayor: An Empirical Test.

    Science.gov (United States)

    Foster, Lorn S.

    1978-01-01

    During the past ten years Blacks have increased their participation in the urban political process. In a few urban areas, such as Newark and Detroit, Blacks constitute an electoral majority and have elected Black mayors. (Author/RLV)

  17. Nivel de autotrascendencia en un grupo de adultos mayores mexicanos

    Directory of Open Access Journals (Sweden)

    Raúl Fernando Guerrero Castañeda

    2017-01-01

    Full Text Available Introducción: La autotrascendencia es una expansión multidimensional personal, una conexión con los demás, el entorno y/o una entidad superior, está relacionada con el bienestar personal del adulto mayor. Objetivo: Determinar el nivel de autotrascendencia de un grupo de adultos mayores mexicanos. Materiales y Métodos: Estudio descriptivo de corte transversal; realizado en tres centros gerontológicos de Celaya, Guanajuato, México, muestra probabilística aleatoria n=118. Se incluyeron adultos mayores que acudían a los centros gerontológicos, hombres y mujeres, ≥ 60 años. Se utilizó la Escala de Autotrascendencia en español con valor resultante entre 15 y 60 (mayor puntaje = mayor autotrascendencia. Se realizó prueba piloto con 40 adultos mayores con Alpha de Cronbach de 0.80. Análisis estadístico descriptivo para variables categóricas (frecuencias y porcentajes, para variables numéricas: medidas de tendencia central y dispersión. Resultados: Media de Autotrascendencia fue 51.36. Se identificaron con “Encontrando significado en mis creencias espirituales” (85.6% y “Disfrutando mi ritmo de vida” (81.4%; hubo diferencia estadísticamente significativa en la media de Autotrascendencia (p˂0.05 por sexo, siendo mayor el nivel en las mujeres. No hubo diferencia entre grupos de edad. Discusión y Conclusiones: La media de autotrascendencia refleja un nivel alto, en comparación con otros estudios y se reportó entre 75-84 años una media mayor. Los adultos mayores se identifican con características como la religión y el disfrute de la vida. La Escala de Autotrascendencia se puede usar en adultos mayores mexicanos ya que demostró un buen nivel de consistencia interna. Cómo citar este artículo: Guerrero RF, Lara R. Nivel de autotrascendencia en un grupo de adultos mayores mexicanos. Rev Cuid. 2017; 8(1: 1476-87. http://dx.doi.org/10.15649/cuidarte.v8i1.354

  18. Significado de ser docente para el adulto mayor sanfernandino

    OpenAIRE

    Martina, Martha; Santos, Gladys; Lema, Julia

    2013-01-01

    Objetivos: Comprender el significado de ser docente para el adulto mayor de la Facultad de Medicina de San Marcos y describir las motivaciones que determinan, de alguna forma, su decisión de postergar su retiro, no obstante haber cumplido con los requisitos legales para la jubilación. Diseño: Estudio de caso cualitativo. Institución: Facultad de Medicina, UNMSM. Participantes: Docentes adulto mayores de la Facultad de Medicina. Intervenciones: Entrevista a profundidad. Principales medidas de ...

  19. Overview of Multi-DC-Bus Solutions for DC Microgrids

    DEFF Research Database (Denmark)

    Ricchiuto, D.; Mastromauro, R.A.; Liserre, Marco

    2013-01-01

    DC Microgrids have recently received a lot of attention in the last years due to high penetration of renewable energy sources as well as distributed energy storage systems. In the future DC microgrids could be preferable respect to AC microgrids in terms of redundancy since multi-DC-Bus solutions...... could provide a continuative power supply to the loads. An overview of Multi-DC-Bus solutions is presented in this paper. The performances are compared on the basis of possible DC microgrid configurations, redundancy, different DC voltage levels....

  20. Prevalencia de anemia y factores asociados en adultos mayores peruanos

    Directory of Open Access Journals (Sweden)

    Carolina Tarqui-Mamani

    Full Text Available Objetivos. Determinar la prevalencia de anemia y factores asociados en los adultos mayores del Perú. Materiales y métodos. Se realizó un estudio transversal durante el año 2011. El muestreo fue probabilístico, estratificado y multietápico. La muestra de viviendas fue 5792 y se incluyó 2172 adultos mayores. Se definió anemia como hemoglobina 23 a 80 años (OR 2,1; IC 95%: 1,4-3,0 y la delgadez (OR 1,7; IC 95%:1,2-2,3 se asociaron con la anemia. Los departamentos con mayor prevalencia de anemia fueron Ayacucho (57,6%, Ancash (40,1%, Lambayeque (37,7% y Apurímac (36,9%. Conclusiones. Aproximadamente la cuarta parte de los adultos mayores tuvieron anemia, siendo más predominante en los analfabetos, procedentes de áreas rurales y pobres. La mayor edad y la delgadez se asocian con la presencia de anemia en los adultos mayores peruanos

  1. Multi Bus DC-DC Converter in Electric Hybrid Vehicles

    Science.gov (United States)

    Krithika, V.; Subramaniam, C.; Sridharan, R.; Geetha, A.

    2018-04-01

    This paper is cotncerned with the design, simulation and fabrication of the prototype of a Multi bus DC- DC converter operating from 42V DC and delivering 14V DC and 260V DC. As a result, three DC buses are interconnected through a single power electronic circuitry. Such a requirement is energized in the development of a hybrid electric automobile which uses the technology of fuel cell. This is implemented by using a Bidirectional DC-DC converter configuration which is ideally suitable for multiple outputs with mutual electrical isolation. For the sake of reduced size and cost of step-up transformer, selection of a high frequency switching cycle at 10 KHz was done.

  2. dc Arc Fault Effect on Hybrid ac/dc Microgrid

    Science.gov (United States)

    Fatima, Zahra

    The advent of distributed energy resources (DER) and reliability and stability problems of the conventional grid system has given rise to the wide spread deployment of microgrids. Microgrids provide many advantages by incorporating renewable energy sources and increasing the reliability of the grid by isolating from the main grid in case of an outage. AC microgrids have been installed all over the world, but dc microgrids have been gaining interest due to the advantages they provide over ac microgrids. However the entire power network backbone is still ac and dc microgrids require expensive converters to connect to the ac power network. As a result hybrid ac/dc microgrids are gaining more attention as it combines the advantages of both ac and dc microgrids such as direct integration of ac and dc systems with minimum number of conversions which increases the efficiency by reducing energy losses. Although dc electric systems offer many advantages such as no synchronization and no reactive power, successful implementation of dc systems requires appropriate protection strategies. One unique protection challenge brought by the dc systems is dc arc faults. A dc arc fault is generated when there is a gap in the conductor due to insulation degradation and current is used to bridge the gap, resulting in an arc with very high temperature. Such a fault if it goes undetected and is not extinguished can cause damage to the entire system and cause fires. The purpose of the research is to study the effect of the dc arc fault at different locations in the hybrid ac/dc microgrid and provide insight on the reliability of the grid components when it is impacted by arc faults at various locations in the grid. The impact of dc arc fault at different locations on the performance of the PV array, wind generation, and constant power loads (CPL) interfaced with dc/dc converters is studied. MATLAB/Simulink is used to model the hybrid ac/dc microgrid and arc fault.

  3. Early Oscillation Detection for DC/DC Converter Fault Diagnosis

    Science.gov (United States)

    Wang, Bright L.

    2011-01-01

    The electrical power system of a spacecraft plays a very critical role for space mission success. Such a modern power system may contain numerous hybrid DC/DC converters both inside the power system electronics (PSE) units and onboard most of the flight electronics modules. One of the faulty conditions for DC/DC converter that poses serious threats to mission safety is the random occurrence of oscillation related to inherent instability characteristics of the DC/DC converters and design deficiency of the power systems. To ensure the highest reliability of the power system, oscillations in any form shall be promptly detected during part level testing, system integration tests, flight health monitoring, and on-board fault diagnosis. The popular gain/phase margin analysis method is capable of predicting stability levels of DC/DC converters, but it is limited only to verification of designs and to part-level testing on some of the models. This method has to inject noise signals into the control loop circuitry as required, thus, interrupts the DC/DC converter's normal operation and increases risks of degrading and damaging the flight unit. A novel technique to detect oscillations at early stage for flight hybrid DC/DC converters was developed.

  4. Actitudes europeos ante el envejecimiento y los personas mayores

    Directory of Open Access Journals (Sweden)

    ALAN WALKER

    1996-01-01

    Full Text Available n este artículo se realiza un análisis comparativo de las actitudes ante el envejecimiento y las personas mayores en los doce estados miembros de la unión europea. Está basado en datos originales de encuesta y se centra en la relación entre las personas mayores y los jovenes, la jubilación y las pensiones, los trabajadores de edad y el empleo, la atención social a las personas mayores y la política de la vejez. Por lo tanto, el artículo intenta proporcionar un resumen de las principales dimensiones de las actitudes publicas ante el envejecimiento en la union europea.

  5. Thyristors for dc transmission

    Energy Technology Data Exchange (ETDEWEB)

    1966-05-06

    As a first stage towards determining the feasibility of applying thyristors to hvdc converter terminals, the Westinghouse Electric Corporation has built a converter laboratory capable of testing thyristors under conditions similar to those which would have to be met in a 200 kV dc system. The equipment has been designed to test a 5 kV 600 A group of thyrisotrs, elevated 200 kV above earth. This rating has been chosen so that there would be a sufficient number of thyristors in series to enable the gating and voltage division characteristics to be investigated and at the same time the group could be operated at a potential equivalent to a complete 200 kV dc bridge.

  6. TOPOLOGICAL REVIEW AND ANALYSIS OF DC-DC BOOST CONVERTERS

    Directory of Open Access Journals (Sweden)

    V. INDRA GANDHI

    2017-06-01

    Full Text Available DC voltage boost up is essential in numerous applications; especially considering Photovoltaic (PV based renewable power generation system. The conventional DC-DC boost converter is the most admired configuration for this scheme, even if the converter efficiency is restricted at duty cycle near to maximum value. In order to find solution to the problem and improve its conversion capability, many converter configurations have been implemented so far. With this circumstance, this research work proposes to give overview of a few most imperative research works related to DC-DC boost converters. Some configurations are covered and classified basically based on the application. The major benefits and disadvantages related to the available techniques are also briefly conveyed. At last, a proper evaluation is recognized among the important types of DC-DC boost converters in terms of efficiency, number of components, and stability.

  7. Prevalencia de trastornos temporomandibulares en el adulto mayor institucionalizado

    Directory of Open Access Journals (Sweden)

    Zenia Masiel Criado Mora

    Full Text Available Introducción: los trastornos temporomandibulares (TTM son una serie de signos y síntomas buco faciales de etiología multifactorial. En Cuba existen varias investigaciones que tratan sobre los TTM %sobre todo en jóvenes dentados% no conociéndose amplias referencias de este tipo de estudio en el adulto mayor. Objetivo: identificar la prevalencia de TTM en los adultos mayores institucionalizados, los signos y síntomas más frecuentes según edad y sexo. Métodos: se realizó un estudio descriptivo transversal en 113 adultos mayores de ambos sexos, institucionalizados en dos hogares de ancianos de la Habana, de marzo a abril de 2012. Se aplicó una encuesta donde se recogió sexo, edad, signos y síntomas. Las manifestaciones clínicas evaluadas fueron: la presencia de dolor muscular, dificultad al movimiento de abertura y cierre, dolor articular, dolor muscular articular, ruidos articulares, limitación de la abertura bucal, limitación de los movimientos de lateralidad y propulsión, desviación de la mandíbula. Resultados: el 40,70 % de los adultos mayores estudiados, presentaron afectación en la articulación temporomandibular. Los ruidos articulares fue el síntoma con mayor predominio en todos los grupos etarios (76,08 %, afectando al 82,35 % de los hombres y al 72,41 % de las mujeres. Seguido por el dolor muscular que se manifestó en el 52,17 % de los afectados, con mayor porcentaje en mujeres (58,62 % que en hombres (41,17 %. La dificultad para realizar los movimientos de abertura y cierre se detectó en el 28,26 % de los afectados con mayor prevalencia en el sexo femenino (34,48 % que en el masculino (17,14 %. Conclusiones. se observó una elevada prevalencia de TTM en los adultos mayores estudiados. Los signos y síntomas más frecuentes por edad y sexo fueron los ruidos articulares y el dolor muscular y la dificultad para realizar los movimientos de abertura y cierre.

  8. INTERVENCIÓN PSICOLÓGICA EN ADULTOS MAYORES

    Directory of Open Access Journals (Sweden)

    Ana Fernanda Rodríguez Uribe

    2010-01-01

    Full Text Available El objetivo de este artículo es plantear una propuesta de intervención psicológica dirigida a adultos mayores institucionalizados y no institucionalizados; para ello se tomó como referencia la situación actual del adulto, los estudios realizados entorno a esta etapa y específicamente lo relacionado con el diseño de programas de intervención, para finalmente exponer la propuesta de intervención psicológica que pretende no solo mejorar la calidad de vida del adulto mayor, sino abarcarlo desde sus diversas áreas de funcionamiento.

  9. Prevalencia de la dependencia funcional en personas mayores

    OpenAIRE

    Gázquez Linares, José Jesús; Pérez Fuentes, Mª del Carmen; Mercader Rubio, Isabel; Molero Jurado, Mª del Mar

    2011-01-01

    La consecuencia más inmediata del envejecimiento de la población actual, es el incremento de la dependencia. Así, el objetivo de este trabajo, es dar a conocer la prevalencia del nivel de dependencia para las actividades básicas e instrumentales en la población mayor de 60 años, en función del género, estado civil y la edad, seleccionando una muestra total de 1.222 personas. El nivel de dependencia es mayor entre las mujeres para casi todas las actividades básicas, siendo también las personas...

  10. Nivel de autotrascendencia en un grupo de adultos mayores mexicanos

    OpenAIRE

    Raúl Fernando Guerrero Castañeda; Ricardo Lara Pérez

    2017-01-01

    Introducción: La autotrascendencia es una expansión multidimensional personal, una conexión con los demás, el entorno y/o una entidad superior, está relacionada con el bienestar personal del adulto mayor. Objetivo: Determinar el nivel de autotrascendencia de un grupo de adultos mayores mexicanos. Materiales y Métodos: Estudio descriptivo de corte transversal; realizado en tres centros gerontológicos de Celaya, Guanajuato, México, muestra probabilística aleatoria n=118. Se incluyeron adultos m...

  11. NIVEL DE AUTOTRASCENDENCIA EN UN GRUPO DE ADULTOS MAYORES MEXICANOS

    OpenAIRE

    Guerrero Castañeda, Raúl Fernando; Lara Pérez, Ricardo

    2017-01-01

    RESUMEN Introducción: La autotrascendencia es una expansión multidimensional personal, una conexión con los demás, el entorno y/o una entidad superior, está relacionada con el bienestar personal del adulto mayor. Objetivo: Determinar el nivel de autotrascendencia de un grupo de adultos mayores mexicanos. Materiales y Métodos: Estudio descriptivo de corte transversal; realizado en tres centros gerontológicos de Celaya, Guanajuato, México, muestra probabilística aleatoria n=118. Se incluyero...

  12. BIENESTAR PSICOLOGICO: ADULTOS MAYORES, ACTIVOS A TRAVES DEL VOLUNTARIADO

    OpenAIRE

    FERRADA MUNDACA; LESLIE ISABEL; FERRADA MUNDACA; LESLIE ISABEL

    2011-01-01

    El propósito del presente estudio fue establecer el grado de bienestar psicológico en adultos mayores voluntarios del programa "Asesores Seniors" de Senama Región Bio Bio y no voluntarios, usuarios del CESF AM San Pedro de la comuna de San Pedro de la Paz. Corresponde a un estudio cuantitativo, de tipo descriptivo, correlacional y comparativo. La muestra estuvo constituida por 60 adultos mayores, donde 30 de ellos corresponde al grupo de voluntarios y los otros 30 al grupo...

  13. Apoyo social dignificante del adulto mayor institucionalizado. medellin, 2008

    OpenAIRE

    Cardona Arango, Doris; Segura Cardona, Angela María; Ordoñez Molina, Jaime Eduardo; Estrada Restrepo, Alejandro; Osorio Gómez, Jorge Julián; Chavarriaga Maya, Lina Marcela

    2011-01-01

    Objetivo Analizar el apoyo social del adulto mayor residente en los Centros de Bienestar del Anciano de Medellín registrados en la Secretaría de Bienestar Social en el año 2008. Materiales Estudio descriptivo transversal, que abordó algunas características relacionadas con el apoyo social recibido por 276 adultos mayores institucionalizados en 39 centros de protección social, con fuente de información primaria. El análisis de la información fue univariado y bivariado. Resultados Los institu...

  14. An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications

    OpenAIRE

    Liwen Pan; Chengning Zhang

    2016-01-01

    This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs). The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for m...

  15. VOLUNTARIADO DE MAYORES: EJEMPLO DE ENVEJECIMIENTO PARTICIPATIVO Y SATISFACTORIO

    Directory of Open Access Journals (Sweden)

    María Silveria Agulló Tomás

    2002-01-01

    Full Text Available El objetivo general de este trabajo estriba en desarrollar el tema del voluntariado de mayores como un claro ejemplo de envejecimiento participativo y saludable. En la primera parte se definen los conceptos utilizados y se refleja el «envejecimiento activo» como expresión de una necesidad social más que sólo una tendencia en boga. La participación social de los mayores es destacada como interés prioritario tanto desde las instituciones políticas como socio-económicas. En la segunda, se ofrecen algunos datos e informaciones que ayudan a dibujar una panorámica internacional sobre la situación de los mayores como voluntarios. En la tercera se desarrollan las distintas actividades, tipología, opiniones y vivencias de voluntarios mayores en nuestro contexto español. Al final, entre otras conclusiones y propuestas, se subraya la relevancia de continuar y hacer realidad un «envejecimiento participativo», pero, eso sí, evitando el derrumbe hacia la «explotación» humana para construir una vejez más saludable y justa acorde con los principios básicos de toda sociedad democrática.

  16. Mayors and Public Education: The Case for Greater Involvement

    Science.gov (United States)

    Usdan, Michael D.

    2006-01-01

    Over the last generation, a new politics of education has evolved throughout the United States. Since the 1983 watershed report "A Nation at Risk" (National Commission on Excellence in Education, 1983), the country's most influential business and political leaders--and, more recently, mayors--have spearheaded efforts to improve student achievement…

  17. ALGUNOS ASPECTOS A CONSIDERAR SOBRE LA SEXUALIDAD DEL ADULTO MAYOR

    Directory of Open Access Journals (Sweden)

    Zoila Edith Hernández Zamora

    2008-12-01

    Full Text Available La presente investigación expone, a partir de una serie de entrevistas realizadas a una muestra de adultos mayores, aspectos relativos a la satisfacción general en la vida, así como las actitudes, conocimientos y prácticas de la sexualidad de un grupo de adultos mayores que asisten regularmente a una estancia diurna de la ciudad de Xalapa, Veracruz, México, misma que fue diseñada especialmente para este grupo etario. Se encontraron diferencias estadísticamente significativas entre la actitud hacia el ejercicio de la sexualidad de las personas mayores entre los hombres y las mujeres de la muestra, y entre .las personas que tienen pareja con relación a las que no tienen; así como que hay una diferencia estadísticamente significativa entre aquellas personas que tiene una o ninguna enfermedad y las que tienen dos o más enfermedades con respecto a su frecuencia de actividad sexual. Es de resaltar la escasez de conocimientos sobre aspectos básicos de la sexualidad que poseen estas personas mayores, lo que hace necesario el establecimiento de programas educativos que incluyan al personal de salud y a los mismos senectos.

  18. Will Mayor De Blasio Turn Back the School Reform Clock?

    Science.gov (United States)

    Meyer, Peter

    2014-01-01

    While heads were spinning, policy watchers seemed genuinely perplexed by New York City's Mayor de Blasio's education opinions. De Blasio opposed many of Bloomberg's reform efforts despite the achievement gains realized by the nation's largest school district during the last 12 years. Yet on close reading, de Blasio's nine-page education plan…

  19. Creatividad, creencias paranormales y deterioro cognitivo en personas mayores

    Directory of Open Access Journals (Sweden)

    Inmaculada Méndez

    2015-08-01

    Full Text Available En el caso de las personas mayores, el pensamiento estético y la creatividad son formas de mantener activas la mente y la imaginación, contribuyendo a prevenir el deterioro cognitivo. Asimismo tener un sistema de creencias religiosas o incluso un sistema de creencias o experiencias paranormales ha demostrado ser beneficioso sobre la salud de los ancianos. El objetivo del estudio fue estudiar la relación entre la creatividad, el grado de deterioro cognitivo y las creencias paranormales. Se analizaron si existían diferencias atendiendo a características sociodemográficas. A un grupo de 36 personas mayores (16 varones con edades comprendidas entre los 66 y 95 años se le administró el Mini-Examen-Cognoscitivo (MEC, el Test CREA y la Escala Mejorada de Creencias Paranormales. Los resultados principales destacan que: los sujetos con mejor estado cognitivo son los más creativos; los menos creativos poseían más Creencias religiosas tradicionales e incluso mayor superstición; los ancianos con mejor estado cognitivo eran los menos supersticiosos. Es destacable que los varones eran más creativos, mientras que las mujeres destacaban en creencias religiosas tradicionales. El estudio permite reflexionar sobre la importancia de que los profesionales que trabajen con personas mayores lleven a cabo programas que favorezcan la creatividad e incluso recaben información sobre el sistema de creencias.

  20. Resiliencia en cuidadores familiares de personas mayores dependientes

    Directory of Open Access Journals (Sweden)

    María Crespo

    2015-01-01

    Full Text Available El presente trabajo analiza la distribución de los niveles de resiliencia en cuidadores no profesionales (familiares de personas mayores dependientes, y explora las características que poseen los cuidadores altamente resilientes. Para ello se administró la escala CD-RISC a una muestra de 111 cuidadores. En función de las puntuaciones obtenidas, se distinguieron dos grupos: alta vs. moderada o baja resiliencia. Se analizaron las diferencias entre ambos grupos en las diversas variables que afectan al estrés del cuidador. Aunque hubo diferencias en el estado cognitivo del receptor de cuidado, las mayores diferencias se obtuvieron en las denominadas variables mediadoras, observando en los cuidadores con alta resiliencia mayores puntuaciones en: satisfacción con el apoyo social recibido, autoeficacia para controlar los pensamientos negativos, autoestima, autocuidado y extraversión; y siendo estas diferencias estadísticamente significativas. Asimismo los cuidadores altamente resilientes tendieron a manifestar una menor preocupación por los problemas del mayor, y presentaron menores niveles de sintomatología depresiva y ansiosa. Este estudio pone de manifiesto la importancia de la resiliencia como factor de protección en el ámbito del estrés crónico, incorporando aspectos positivos de la adaptación a los modelos teóricos de cuidado, los cuales tradicionalmente se han venido centrando en el desarrollo de sintomatología.

  1. Valores humanos y voluntariado: Un estudio en personas mayores

    Directory of Open Access Journals (Sweden)

    Antonio Ariza-Montes

    2017-02-01

    Diseño/metodología: Tras un análisis exploratorio inicial, se plantea un modelo de regresión logística para determinar en qué medida el catálogo de valores personales que posee un individuo ayuda a explicar la actividad de voluntariado entre las personas mayores. Aportaciones y resultados: Los resultados del modelo permiten afirmar que el hecho de que una persona mayor done o no tiempo a actividades de voluntariado puede ser satisfactoriamente explicado por el conjunto de valores humanos. Los resultados obtenidos revelan que los voluntarios jubilados presentan mayor sentido de la autotrascendencia y predisposición hacia el cambio, a la vez que denotan más aversión hacia la autopromoción y la conservación. Implicaciones prácticas: Para mejorar el nivel de compromiso y la motivación de los voluntarios mayores jubilados, y afrontar con firmeza los retos que amenazan al sector no lucrativo, los responsables de los recursos humanos de las entidades del tercer sector deberán buscar la coherencia entre los valores individuales y la naturaleza de la actividad que va a desempeñar el voluntario, incrementando de este modo el grado de identificación de estas personas. Valor añadido: A pesar de la abundante literatura que relaciona el voluntariado en personas mayores con el bienestar, tanto en términos de salud como de beneficios socioemocionales, y con las motivaciones de este colectivo a la hora de ejercer el voluntariado, no es frecuente hallar investigaciones que adopten como foco de análisis el perfil de los valores personales que incitan a estos individuos a colaborar con causas altruistas.

  2. Model Prediksi Kebutuhan Darah untuk Penderita Talasemia Mayor

    Directory of Open Access Journals (Sweden)

    Dwi Sarwani Sri Rejeki

    2014-02-01

    Full Text Available Pada dua tahun pertama kehidupan penderita talasemia mayor, umumnya menderita anemia dan membutuhkan tranfusi darah. Penelitian ini bertujuan membuat model prediksi kebutuhan darah bagi penderita talasemia mayor. Penelitian observasional dengan desain studi pendekatan potong lintang ini dilakukan pada sampel 79 penderita talasemia mayor yang melakukan transfusi rutin minimal satu bulan satu kali di Rumah Sakit Umum Banyumas, selama tahun 2012. Analisis regresi linier ganda digunakan untuk membuat model prediksi. Hasil penelitian menunjukkan bahwa 80,7% kebutuhan darah penderia talasemia mayor dijelaskan oleh variabel usia, berat badan, dan kadar hemoglobin sedangkan 19,3% dijelaskan oleh sebab-sebab yang lain. Rumus prediksi menyatakan setiap kenaikan usia 1 tahun maka kebutuhan darah akan bertambah sebanyak 0,816 mililiter dan setiap kenaikan 1 kilogram berat badan maka kebutuhan darah akan bertambah 13,4 mililiter serta apabila kadar hemoglobin mengalami penurunan 1 g/dL maka kebutuhan darah akan bertambah sebesar 81 mililiter. Patients with thalassemia major usually present within the first two years of life with severe anemia, need red blood cell transfusion. The objective of this study was to create a prediction model of blood transfusion need for patients with thalassemia mayor. This type of research was observational with cross sectional design. Samples are 79 patients with thalassemia major who perform routine transfusion at least once in a month at Banyumas hospital in 2012. Multiple linier regression analysis was used to create the model. The results showed that 80.7% blood requirements can be explained by variables of weight, haemoglobin level and age, while 19.3% is explained by other causes. Prediction formula states every increment of one year in age, the need for blood will increase by 0.816 millilitres and every increment of one kilogram of body weight, the need for blood will increase 13.4 millilitres, and when the haemoglobin

  3. Las personas mayores a través del cine

    Directory of Open Access Journals (Sweden)

    José Ramón Martínez Riera

    Full Text Available Resumen: El presente artículo hace un recorrido por las diferentes etapas del envejecimiento y de la vida de las personas mayores a través del cine. El cine es un arte que transmite ideas a través de la narración de historias, mediante imágenes que impactan en el aspecto psicoemocional de las personas. El cine nos sitúa en escenarios donde se muestran las relaciones humanas, en contextos difíciles de reproducir, los cuales nos permiten explorar la esfera de los sentimientos frente a situaciones de salud-enfermedad, de ponerse en lugar del “otro”: de la persona que sueña, padece y sufre, de los profesionales que intervienen, de la familia que convive, cuida, sufre con el enfermo, de los amigos... Y entre esos escenarios, sin duda, se encuentra el proceso de envejecimiento y los diferentes factores que influyen en él. Y sin embargo no suele prestársele excesiva atención a la aportación que el cine ha realizado y realiza como elemento de reflexión, análisis, debate y aprendizaje, más allá del mero entretenimiento en el que muchas veces se enmarca el cine. Pero, ¿cómo ha tratado el cine a las personas mayores? ¿cómo aborda las interrelaciones de las personas mayores con su entorno, su familia, su proceso de salud-enfermedad, sus miedos, sus emociones? ¿Trata igual a las personas mayores con independencia de su género? Y lo que puede ser más interesante, ¿contribuye el cine a mitigar o eliminar los tópicos y estereotipos existentes en el imaginario común en torno a las personas mayores?

  4. Council Appointed Mayors in Spain: Effects on Local Democracy

    Directory of Open Access Journals (Sweden)

    María Jesús García García

    2017-03-01

    Full Text Available This paper deals with the influence of having council appointed mayors on local governments. Five elements of local government systems are considered: the electoral system and its influence on the political composition of the local government; the local government structure and the distribution of functions and powers between mayor and council; the role of political parties; scrutiny of the executive and accountability; and citizen participation. This analysis highlights the effect that a council appointed mayor system has in terms of accountability and legitimacy, transparency and efficiency. KEYWORDS Local government systems, directly elected mayors, local governance, council appointed mayors, Local Government Structure; Political Parties; Citizen Participation; Accountability. El presente artículo toma en consideración los efectos que el sistema de elección del Alcalde tiene sobre la democracia local, basándose en la consideración cinco aspectos: el sistema electoral y su influencia en la composición política de las administraciones locales; la estructura de la administración local y la distribución de funciones entre los alcaldes y el pleno municipal; el papel de los partidos políticos; los mecanismos de control del ejecutivo local y la participación ciudadana. El estudio subraya especialmente la incidencia que el sistema de elección del alcalde por los concejales tiene en relación con los principios de responsabilidad, legitimidad, transparencia y eficiencia de la gestión local. PALABRAS CLAVE Gobierno local, elección directa de los alcaldes, elección indirecta de los alcaldes, estructura del gobierno local, partidos políticos, participación ciudadana, responsabilidad política.

  5. La calidad de vida del adulto mayor con Artritis Reumatoidea

    Directory of Open Access Journals (Sweden)

    Clara Gallardo

    2017-05-01

    Full Text Available Objetivo determinar la atención de Enfermería y su incidencia en la calidad de vida del adulto mayor con artritis reumatoidea atendidos en el subcentro de salud de Ambatillo en el período Julio – Diciembre 2013. Métodos y materiales: Estudio no experimental de diseño descriptivo aplicando técnicas de observación y cuestionario cuya población fue de 30 adultos mayores en los que se detectó la necesidad de investigar la problemática, cuyos resultados indican que los principales problemas que presentan los pacientes son: dolor e inflamación articular, incapacidad músculo esquelética, discapacidad etc. Re- sultados: La problemática que se aborda es la calidad de vida del adulto mayor con esta patología pues muchas veces no se da una atención basada en el estado emocional, respuesta fisiológica, aspecto físico al que se enfrenta tanto el paciente como su núcleo familiar.es asì que el 69% de adultos mayores con artritis reumatoidea , la misma manera el 75% del personal de enfermería que labora en el Subcentro de salud de Ambatillo Conclusiones: Una vez evidenciada la problemática de estudio se presenta como propuesta la elaboración de una Guía de Atención de Enfermería el mismo que permitirá valorar en forma integral, priorizar las necesidades de atención y brindar cuidados específicos en el adulto mayor con artritis reumatoidea.

  6. On and off controlled resonant dc-dc power converter

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter comprising an input side circuit comprising a positive and a negative input terminal for receipt of an input voltage or current and an output side circuit comprising positive and negative output terminals for supply of a converter...... output voltage and connection to a converter load. The resonant DC-DC power converter further comprises a rectification circuit connected between an output of a resonant network and the output side circuit. The resonant network is configured for alternatingly being charged from the input voltage...... or current and discharged through the rectification circuit by a first controllable switch arrangement in accordance with a first switch control signal. A second controllable switch arrangement of the resonant DC-DC power converter is configured to select a first impedance characteristic of the resonant...

  7. DC Cable for Railway

    Science.gov (United States)

    Tomita, Masaru

    The development of a superconducting cable for railways has commenced, assuming that a DC transmission cable will be used for electric trains. The cable has been fabricated based on the results of current testing of a superconducting wire, and various evaluation tests have been performed to determine the characteristics of the cable. A superconducting transmission cable having zero electrical resistance and suitable for railway use is expected to enhance regeneration efficiency, reduce power losses, achieve load leveling and integration of sub-stations, and reduce rail potential.

  8. Auxiliary resonant DC tank converter

    Science.gov (United States)

    Peng, Fang Z.

    2000-01-01

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  9. PENGGUNAAN FUZZY LOGIC UNTUK KONTROL PARALLEL CONVERTER DC-DC

    Directory of Open Access Journals (Sweden)

    Bambang Prio Hartono

    2012-09-01

    Full Text Available Abstract: Using system fuzzy logic as control  technology have been used on low load dc-dc converter with combined parallel compiled  dc-dc converter can  obtain big load.   With existence of differrence of component parameter and each parallel compiled converter can obtained different current  and voltage output.  Function of controller  for to do adjustment, so that current which is applied  to  load by each converter  can be obtained  difference error as small as possible or same. The object of research is developing design of large signal dc-dc converter which is  combined with using  FLC so that  obtain  better performance.  To get better performance have been made plant model and simulation with CDE method.  The more systematic  system and design is needed to overcome bigger load  on dc-dc converter, so that parallel  compiled current master slave control system on dc-dc converter with using fuzzy logic  controller is used. Result of  research showed that error or difference of  current  which is applied to load can handled by fuzzy logic  controller.  Technic of current and voltage controller co to do adjustment current and voltage distribution  equally to load.  Distribution of iL1,iL2 and  output voltage Vo on dc-dc  converter with load 2,25 until  7,875 and voltage  100  until 120 volt,  load current beetwen  12 until 48, % relatif  error  Vo  0,4% until  0,9%.

  10. Step-Up DC-DC Power Converter

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a step-up DC-DC power converter which comprises a primary side circuit and a secondary side circuit coupled through a galvanic isolation barrier. The primary side circuit comprises a positive and a negative input terminal for receipt of an input voltage and an input...... being charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier in accordance with a switch control signal to produce the converter output voltage. The step-up DC-DC power converter comprises an electrical short-circuit connection across the galvanic...

  11. DC Distribution Systems and Microgrids

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Anvari-Moghaddam, Amjad; Quintero, Juan Carlos Vasquez

    2017-01-01

    summarized. Due to its attractive characteristics in terms of compliance with modern generation, storage and electronic load technologies, high reliability and current carrying capacity, as well as simple control, DC systems are already an indispensable part of power systems. Moreover, the existing......A qualitative overview of different hardware topologies and control systems for DC MGs has been presented in this chapter. Some challenges and design considerations of DC protections systems have also been discussed. Finally, applications of DC MGs in emerging smart grid applications have been...... challenges such as protection issues will be effectively resolved in the near future due to fast progress of semiconductor technology which is a key enabler cheap and reliable future DC solid-state protection systems. Therefore, it is the view of the author that more and more DC systems will appear...

  12. Adultos mayores cuidadores: sobrecarga y dimensión afectiva

    Directory of Open Access Journals (Sweden)

    Serrana Banchero

    2017-05-01

    Full Text Available Este trabajo plantea la relación entre la sobrecarga del cuidador y la dimensión afectiva del cuidado en personas mayores cuidadoras. En la actualidad el cuidado es entendido como una problemática social pública, y por lo tanto objeto de políticas públicas. Uruguay es un país envejecido debido a los cambios socio-demográficos que han acontecido por lo que han aumentado las situaciones de dependencia y las demandas de cuidados. De este modo, las personas mayores no solo son receptores sino también proveedores de cuidados. El cuidado implica la dimensión material, económica y afectiva, y los cuidadores como consecuencia de su tarea de cuidar, pueden experimentar el síndrome de sobrecarga del cuidador. Se trata de un diseño cuali-cuantitativo y consiste en un estudio de caso utilizando entrevistas individuales con aplicación de instrumentos según la categorización de la muestra finalista que fue Personas Mayores Cuidadoras y no Cuidadoras. Se analizará la variable sobrecarga del cuidador con las características de la relación cuidador-cuidado. La muestra es finalista y se constituyó por 74 personas mayores usuarios regulares del Subprograma Adultos Mayores del Programa Apex-Cerro (UdelaR de la ciudad de Montevideo, Uruguay. Los resultados mostraron que aparece una visión totalizante del cuidado, así como relatos autorreferenciales. El 29,7% son personas mayores cuidadoras, de los cuales el 15,7% presentan el síndrome de sobrecarga del cuidador (siendo todas mujeres y la edad mediana de 65,5 años. En el análisis de la dimensión afectiva del cuidado se observan características de un tipo de vínculo co-dependiente entre el cuidador y el cuidado.

  13. Bienestar psicológico subjetivo y personas mayores residentes

    Directory of Open Access Journals (Sweden)

    Ana Concepción Flecha García

    2014-12-01

    Full Text Available La mejora del bienestar psicológico subjetivo y, con él, la calidad de vida de las personas mayores residentes es el propósito esencial de este trabajo. Los teóricos destacan la importancia que desempeña el bienestar subjetivo sobre la calidad de vida y su interés en la experiencia de envejecer. Concebimos la calidad de vida como un concepto multidimensional que engloba componentes objetivos y subjetivos referidos al bienestar físico y psico-social de las personas, y su evaluación incluye la percepción subjetiva que tiene el sujeto de estas dimensiones. Entendemos el bienestar psicológico subjetivo, como la valoración positiva, afectiva y cognitiva, de bienestar y satisfacción con la vida entendida como “estar y sentirse bien en el presente” y, “estar y sentirse bien con el propio recorrido vital”.El principal objetivo del estudio es conocer las necesidades de los residentes relacionadas con los componentes específicos del bienestar y satisfacción vital que la investigación revela mas asociados a las personas mayores –vínculos personales, vida activa, reminiscencia y recuerdos felices, optimismo-, y la satisfacción vital; conocer la conexión entre estas dimensiones e identificar posibles factores relacionados con las mismas, completan el fin de este trabajo.Se plantea un modelo metodológico que permite recoger el sentimiento y opinión de las personas mayores desde su propia experiencia de bienestar y satisfacción vital. El enfoque y su carácter interpretativo favorecen la comprensión e interpretación de la información tal y como es percibida por los participantes que viven y se relacionan en un determinado contexto social. Se elige para tal fin la orientación , realizando el posterior. Se recoge la información mediante una entrevista semiestructurada elaborada en base a los fines propuestos. La muestra se compone de 66 personas seleccionas en

  14. propiedades psicométricas en adultos mayores

    Directory of Open Access Journals (Sweden)

    Armando Rivera-Ledesma

    2013-01-01

    Full Text Available La presente investigación propone la adaptación al español y validación de la Escala de Soporte Social (ESS-AM de Tagaya, Okuno, Tamura y Davis (2000, conducida en cuatro muestras independientes de adultos mayores de la Ciudad de México. La escala, de ocho reactivos, mide la percepción de apoyo social mediante un solo factor que explica el 60,7% de la varianza, con una consistencia interna a de 0,84 y correlaciones negativas significativas con la variable soledad. Con base en ello, se concluye que la ESS-AM es un instrumento confiable, útil y sencillo en funciones de tamizaje para evaluar si el adulto mayor cuenta con adecuados niveles de apoyo social percibido.

  15. Intervención de trabajo social con adultos mayores

    Directory of Open Access Journals (Sweden)

    Yesica Rodríguez Montañez

    2003-01-01

    Full Text Available El artículo presenta las metodologías de intervención del Trabajo Social con adultos mayores realizando un recorrido por los términos envejecimiento y vejez, haciendo énfasis en la importancia de la pérdida en la concepción de la misma . Se realiza un aná

  16. Usos de las herramientas digitales entre las personas mayores

    Directory of Open Access Journals (Sweden)

    Javier Fombona Cadavieco

    2012-10-01

    Full Text Available Una sociedad «multiedades» supone diseñar y crear nuevos espacios de aprendizaje y comunicación, capaces de gestionar la demanda existente por parte de las personas mayores. En este artículo, se aborda la relación de las personas mayores con las tecnologías de la información y la comunicación (TIC y para ello se plantean dos objetivos: el primero va dirigido a conocer los recursos tecnológicos que utilizan y el segundo, a describir objetivamente los tipos de uso que estas personas hacen de las TIC. Para ello, se utiliza la técnica de encuesta, cuyos resultados son contrastados mediante grupos de discusión. En el estudio participaron 215 personas mayores usuarias de las TIC y siete grupos de discusión de cinco personas cada uno. Los resultados encontrados indican que los recursos que más utilizan los mayores son, los ordenadores e Internet y el uso que hacen de los mismos se ha agrupado en cuatro grandes categorías: formación, información, comunicación y entretenimiento, no encontrándose diferencias significativas en función del género o de la edad y sí se encontraron diferencias en cuanto a la disponibilidad de dichos recursos para uso particular en función del nivel de estudios.

  17. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

  18. SCM Handbooks for dc-to-dc Converters

    Science.gov (United States)

    Lee, F.; Mohmoud, M.; Yu, Y.

    1984-01-01

    Two documents aid in design of control modules for dc-to-dc converters. Features of SCM include: Adaptive stability, power component stress limiting, implementation of various control laws, unified design approach. Analysis and quidelines contained in handbooks enable engineer to design SCM circuit and confidently predict resulting overall performance.

  19. Sheppard-Taylor Isolated High Boost DC-DC Converter

    DEFF Research Database (Denmark)

    Chub, Andrii; Siwakoti, Yam Prasad; Vinnikov, Dmitri

    2017-01-01

    This paper presents a new galvanically isolated step-up dc-dc converter intended for low-power but high step-up applications. The proposed converter is capable of regulating output voltage within a wide range of the input voltage or load variations. In contrast to competitors, the converter can...

  20. Dc-To-Dc Converter Uses Reverse Conduction Of MOSFET's

    Science.gov (United States)

    Gruber, Robert P.; Gott, Robert W.

    1991-01-01

    In modified high-power, phase-controlled, full-bridge, pulse-width-modulated dc-to-dc converters, switching devices power metal oxide/semiconductor field-effect transistors (MOSFET's). Decreases dissipation of power during switching by eliminating approximately 0.7-V forward voltage drop in anti-parallel diodes. Energy-conversion efficiency increased.

  1. A Current-Fed Isolated Bidirectional DC-DC Converter

    DEFF Research Database (Denmark)

    Sun, Xiaofeng; Wu, Xiaoying; Shen, Yanfeng

    2017-01-01

    This paper proposes a current-fed isolated bidirectional DC-DC converter (CF-IBDC) which has the advantages of wide input voltage range, low input current ripple, low conduction losses, and soft switching over the full operating range. Compared with conventional CF-IBDCs, the voltage spikes...

  2. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification is ca...

  3. La competencia mediática en personas mayores

    Directory of Open Access Journals (Sweden)

    Isidro Marín Gutiérrez

    2013-07-01

    Full Text Available Este artículo ha sido realizado gracias al proyecto I+D+i titulado “La competencia en comunicación audiovisual en un entorno digital” (I+D: EDU 2010-21395-C03 financiado por el Ministerio de Ciencia y Tecnología del Gobierno de España. En ella analizamos el pretest que evaluaba la competencia mediática de personas mayores de 60 años de La Rioja y de Huelva. Los resultados arrojados fueron tenidos en cuenta para el proceso de encuestación que se está realizando actualmente en 10 provincias españolas con una muestra de 615 personas mayores de 60 años. En este artículo estudiaremos el estado de la cuestión en torno a las competencias mediáticas de las personas mayores de 60 años.

  4. Resocialización en el Adulto Mayor

    Directory of Open Access Journals (Sweden)

    Zandra Liliana Cabara

    2004-11-01

    Full Text Available Este artículo plantea un estudio sobre la descripción de métodos de resocialización en el adulto mayor, evidenciando sus potencialidades como auto transformador de su mundo circundante dejando de Iado preconceptos sobre la vejez. Las reflexiones que se plantean en este articulo son producto de un estudio preliminar, don de se aplicó una prueba piloto a tres adultos mayores de diferentes niveles socioculturales pero pertenecientes al mismo estrato económico que se encuentran formando parte de un grupo organizado de atención integral al Adulto Mayor, coordinado por una Fundación Gerontológica en el municipio de Duitama. Se hace un análisis comparativo mediante un método de investigación cualitativa y descriptiva. Restaría, profundizar en la investigación e incluir un estudio comparativo de abuelos con características similares no pertenecientes a grupos organizados.

  5. A DC Transformer

    Science.gov (United States)

    Youngquist, Robert C.; Ihlefeld, Curtis M.; Starr, Stanley O.

    2013-01-01

    A component level dc transformer is described in which no alternating currents or voltages are present. It operates by combining features of a homopolar motor and a homopolar generator, both de devices, such that the output voltage of a de power supply can be stepped up (or down) with a corresponding step down (or up) in current. The basic theory for this device is developed, performance predictions are made, and the results from a small prototype are presented. Based on demonstrated technology in the literature, this de transformer should be scalable to low megawatt levels, but it is more suited to high current than high voltage applications. Significant development would be required before it could achieve the kilovolt levels needed for de power transmission.

  6. The performance of the DC motor by the PID controlling PWM DC-DC boost converter

    OpenAIRE

    Can, Erol; Sayan, Hasan Hüseyin

    2017-01-01

    This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulati...

  7. 75 FR 61989 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-8-31, DC-8-32, DC-8-33, DC-8-41...

    Science.gov (United States)

    2010-10-07

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and... to all of the McDonnell Douglas Corporation airplanes identified above. The existing AD currently... the following new airworthiness directive (AD): 2010-21-03 McDonnell Douglas Corporation: Amendment 39...

  8. Triple voltage dc-to-dc converter and method

    Science.gov (United States)

    Su, Gui-Jia

    2008-08-05

    A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

  9. Prevalencia de depresión mayor en adultos mayores atendidos ambulatoriamente en un hospital de lima metropolitana

    Directory of Open Access Journals (Sweden)

    Magnolia Matutti Rosas

    2016-12-01

    Full Text Available RESUMEN: El objetivo del presente estudio es describir, analizar prevalencia y factores de riesgo predictivo asociado a depresión mayor, en adultos mayores atendidos en consulta ambulatoria de psiquiatría de un hospital, y en un grupo de adultos mayores no asegurados. Se evaluó a 79 adultos mayores no asegurados de una comunidad del Callao y a 221 pacientes con depresión y depresión comórbida, atendidos en consulta ambulatoria de psiquiatría. Se aplicó una encuesta de consumo de medicamentos. Los resultados indican que los factores demográficos son independientes de depresión en ambos grupos (OR=1.792, IC95%=0.573-5.606, edad; OR=1.123, IC95%=0.435-4.768, sexo; OR=2.344, IC95%=0.325-16.928, autopercepción de salud; OR=1.905, IC95%=0.642-2.434, depresión; OR=1. 250, IC95%=0.642-2.434, consumo de medicamentos; OR=1.260, IC95%=0.763-2.084, número de enfermedad. Las personas no aseguradas evidencian depresión comórbida con diabetes mellitus, HTA, Artrosis, encontrando mayor frecuencia en mujeres de 60 a 75 años que en mujeres de 76 años a más. ABSTRACT: Objective: To describe, analyze prevalence and predictive risk factors associated with major depression, seniors attended outpatient psychiatric, and uninsured. Material and Methods: 79 elderly uninsured community surrounding Callao to EsSalud, Survey of Drug Consumption applies; and 221 patients with depression and comorbid depression, diagnosed in Psychiatry Clinic. It was used, the Drug Consumption Survey. Results: Demographic factors are independent of depression in both groups (OR = 1.792, 95%CI = 0.573-5.606, age; OR = 1.123, 95%CI = 0.435-4.768, sex; OR = 2.344, 95%CI = 0.325-16.928, health self-perception; OR = 1,905, 95%CI = 0.642 -2.434, depression;, OR = 1. 250, 95%CI = 0.642-2.434, drug use; OR = 1260, 95%CI = 0.763-2.084, disease number. Uninsured comorbid with depression show DM, hypertension, osteoarthritis, and women age 60-75 It is more frequent than in Group 76

  10. Bi-Directional DC-DC Converter for PHEV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Abas Goodarzi

    2011-01-31

    Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.

  11. Factores asociados al maltrato del adulto mayor de Antioquia, 2012

    Directory of Open Access Journals (Sweden)

    Sara M. Cano

    2015-07-01

    Full Text Available Objetivo: determinar los factores asociados al maltrato del adulto mayor del departamento de Antioquia en el año 2012. Metodología: mediante estudio descriptivo transversal, se caracterizaron los factores demográficos, económicos y de salud mental de la población adulta mayor de Antioquia para el año 2012, con el fin de aportar al análisis de la situación de salud y condiciones de vida del adulto mayor. El estudio se basó en los resultados del instrumento aplicado por la Universidad ces a 4.215 adultos de sesenta años y más de edad, en el cual se indagó sobre percepción de maltrato, funcionamiento cognitivo, nivel de depresión, nivel de ansiedad, apoyo social, escala de recursos sociales, entre otras; los resultados se expandieron a 654.473 adultos del departamento. Resultados: el 72,8% de adultos del departamento son mujeres, 53,7% vive en Medellín, 55% tiene primaria incompleta, 72,9% pertenece a estratos socioeconómicos 1 y 2, 45,1% no registraron ingresos en el último mes, 26,3% tiene riesgo de depresión y 34,4% tiene riesgo de ansiedad, 2,5% reportó haber sufrido descuido, 5,0% necesidades afectivas ignoradas, 1,7% algún caso de agresión física, 0,4% agresión sexual y 1,3%, afirmó haber sufrido maltrato económico. Las variables estrato socioeconómico, tipo de vivienda, etnia, riesgo de depresión, riesgo de ansiedad, riesgo de deterioro cognitivo y red de apoyo fueron las que más ayudaron a explicar la presencia de maltrato. Conclusión: enfrentar este problema requiere de una atención integral a las necesidades de los adultos mayores, participación de todos los sectores de la sociedad y conciencia transgeneracional.

  12. Redes sociales de las mujeres mayores en dos contextos urbanos

    OpenAIRE

    González, M.M. (María)

    2009-01-01

    La enfermera de atención primaria es la responsable de la elaboración de un plan de cuidados adaptado a la población que atendemos,por lo que debe conocer las redes sociales de las personas ya que tener amplias redes puede significar la existencia de personas que ayuden con la medicación, las compras, la limpieza, mejora su seguridad y tienen apoyo en caso de urgencia. Este trabajo investiga esas redes sociales. Analizar las redes sociales de un grupo de mujeres mayores que viven en una i...

  13. Salud y condiciones de trabajo en trabajadores mayores

    Directory of Open Access Journals (Sweden)

    Elena Ordaz Castillo

    2015-09-01

    Full Text Available Introducción: En los últimos años, la población española ha experimentado un crecimiento acelerado de personas mayores. Las previsiones demográficas a corto-medio plazo describen un importante predominio de trabajadores mayores en el mercado laboral. Objetivos: Identificar las diferencias según dos grupos de edad (55 años en la percepción de las condiciones de trabajo y salud de la población trabajadora española. Metodología: Las diferencias entre los dos grupos de edad se analizaron a partir de indicadores de condiciones de trabajo y de salud pertenecientes a la VII Encuesta Nacional de Condiciones de Trabajo del Instituto de Seguridad e Higiene en el Trabajo (VII_ENCT. El análisis consistió en el cálculo de las prevalencias y la odds ratio cruda-ORc y ajustada por sexo con su correspondiente intervalo del confianza al 95%. Resultados: El grupo de trabajadores más jóvenes presentan más riesgo de exposición a seis de los siete indicadores relacionados con las condiciones de trabajo (ruido, vibraciones, carga física, carga mental, autonomía y motivación. No obstante los trabajadores mayores tienen una peor percepción de su estado de salud (ORa= 2,06 [1,75-2,42] y presentan en mayor medida problemas de salud que si bien les conducen a la visita médica más frecuentemente los relacionan menos con su actividad laboral. Conclusiones: A tenor de los resultados, los trabajadores de 55 años y más refieren tener menos quejas respecto a sus condiciones laborales e incluso se sienten más autónomos y motivados. Es el deterioro físico y mental la principal limitación que encuentran estos trabajadores a la hora de ejercer sus tareas. Sería recomendable establecer políticas de promoción de la salud dentro de las empresas para mejorar los indicadores de salud y promover el envejecimiento activo de la población trabajadora española.

  14. La salud de las personas mayores Health among the elderly

    Directory of Open Access Journals (Sweden)

    Elena Gonzalo

    2004-05-01

    Full Text Available Este trabajo explora la existencia de desigualdades de género, de clase y territoriales en la salud de las personas mayores en España, según los datos de la Encuesta Nacional de Salud de 1997, el CMBD de hospitales de 1999, las estadísticas de mortalidad de 1998 y la Encuesta Nacional de Discapacidades de 1999. Se describen las similitudes y diferencias por género y clase social, en las conductas relacionadas con la salud, la salud percibida, los problemas de salud crónicos, la capacidad funcional y el uso de servicios sanitarios. Se comparan, asimismo, las tasas de mortalidad en personas mayores entre las 52 provincias españolas. Las mujeres y los miembros de las clases sociales más desfavorecidas muestran una peor salud percibida. Consumir tabaco o alcohol es más frecuente en los hombres que en las mujeres. La actividad física a esta edad depende, sobre todo, de la actividad cotidiana; los hombres y los miembros de las clases más favorecidas son los que adoptan, en mayor proporción, hábitos sedentarios. Las mujeres presentan problemas de dependencia funcional en mayor medida que los hombres, y entre ellas se observa un claro patrón de desigualdad. Los datos de mortalidad corroboran los hallazgos de otros estudios que sitúan las tasas más altas en el sur de la península.We explore gender, class and geographical inequalities in health of the population aged over 65 years in Spain. We gathered data from the 1997 National Health Survey, 1999 hospital discharge data, 1998 mortality data from vital statistics, and from the 1999 National Survey on Disabilities. Health related behaviors (tobacco and alcohol consumption, eating disorders and physical activity, self-rated health, chronic health problems, functional capacity, and health service utilization are described by gender and social class. Mortality rates among the elderly are compared between the 52 Spanish provinces. Women and members of the lower social classes present worse

  15. Comportamiento de la violencia intrafamiliar en el adulto mayor

    OpenAIRE

    Docampo Santaló, Lourdes; Barreto Lacaba, Rita; Santana Serrano, Caridad

    2009-01-01

    Fundamento: la prevención de la violencia en su marco general y familiar es una prioridad que exige un conocimiento exhaustivo de su magnitud; ya que es observada como un asunto de salud pública por su impacto negativo en la sociedad. Objetivo: caracterizar el comportamiento de la violencia intrafamiliar contra el adulto mayor en el municipio de Nuevitas. Método: se realizó un estudio descriptivo retrospectivo durante el año 2006. De un universo de dos mil ciento seis, setenta y cinco fueron ...

  16. El envejecimiento activo: programa en competencia social con personas mayores

    OpenAIRE

    García Escribano, Rocío

    2014-01-01

    El presente estudio se basa en el aumento de la esperanza de vida y la disminución de la natalidad, lo que conlleva una población más envejecida a la que atender. Se propone un programa sociocultural con personas mayores con la finalidad de promover el envejecimiento activo en este colectivo, favoreciendo su desarrollo social, afectivo, y personal de forma saludable. Para ello, la intervención incluye un programa de formación orientado al entrenamiento en una serie de habilidad...

  17. Metabolismo posprandial en adultos mayores normales de nivel del mar

    Directory of Open Access Journals (Sweden)

    Fausto Garmendia

    2003-06-01

    Full Text Available Objetivo: Determinar las modificaciones normales del metabolismo después de la ingestión de alimentos. Material y Métodos: Se ha estudiado a 33 personas de ambos géneros, adultos mayores, de nivel del mar, tanto en ayunas como después de la ingesta de una mezcla alimenticia consistente en 730 kcal, con 55,4% de grasas, 37,2% de hidratos de carbono y 7,4% de proteínas. Se ha medido el perfil metabólico en ayunas y luego de la ingesta alimentaria, la glucosa, triglicérido (Tg, ácidos grasos no esterificados (AGNE, insulina por métodos convencionales hasta la 6a hora; se ha calculado las concentraciones de colesterol LDL y VLDL utilizando la fórmula de Friedewald; el colesterol no-HDL, mediante la sustracción del valor del colesterol HDL al valor de colesterol total (CT. Resultados: La glicemia se elevó discretamente, regresando a valores basales a la 2a hora; la insulinemia se incrementó durante 4 horas; los triglicéridos comenzaron a elevarse en sangre a partir de la 2a hora y llegaron al máximo a la 4a hora, para luego iniciar el descenso no completo en la 6a hora. Los AGNE disminuyeron a partir de los 30 minutos, llegando al máximo de caída a las 2 horas; luego se apreció un rebote máximo a la 6a hora, inclusive mayor al valor basal. Conclusiones: Estos resultados demuestran que no es suficiente obtener información del metabolismo intermediario en ayunas, sino que el estudio posprandial permite mayor información. Es la primera vez en nuestro país que se obtiene información sobre el metabolismo intermediario en fase posprandial en una muestra de la población normal que se encuentra en una edad de mayor riesgo cardiovascular.

  18. El maltrato a personas mayores atendidas por los Servicios Sociales

    OpenAIRE

    Castilla Mora, María del Rosario

    2015-01-01

    La presente tesis trata sobre el maltrato a las personas mayores (MPM). El MPM es el último tipo de violencia familiar, junto con la violencia de género y el maltrato infantil, por la que los investigadores se han preocupado, siendo hoy día el que tiene menor relevancia, tanto para la sociedad en general como a nivel político. Fue en Gran Bretaña donde los primeros investigadores comenzaron a estudiar el tema, concretamente Baker y Burston, en el año 1975, centrándose en el maltrato fís...

  19. High voltage direct current transmission converters, systems and DC grids

    CERN Document Server

    Jovcic, Dragan

    2015-01-01

    This comprehensive reference guides the reader through all HVDC technologies, including LCC (Line Commutated Converter), 2-level VSC and VSC HVDC based on modular multilevel converters (MMC) for an in-depth understanding of converters, system level design, operating principles and modeling. Written in a tutorial style, the book also describes the key principles of design, control, protection and operation of DC transmission grids, which will be substantially different from the practice with AC transmission grids. The first dedicated reference to the latest HVDC technologies and DC grid developments; this is an essential resource for graduate students and researchers as well as engineers and professionals working on the design, modeling and operation of DC grids and HVDC.

  20. RESONANT STEP-DOWN DC-DC POWER CONVERTERS

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant step-down DC-DC power converter which comprises a primary side circuit and a secondary side circuit coupled through a galvanic isolation barrier. The primary side circuit comprises a positive and a negative input terminal for receipt of an input voltage...... charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier by a semiconductor switch arrangement in accordance with a switch control signal to produce the converter output voltage. The resonant step-down DC-DC power converter comprises an electrical short......-circuit connection across the galvanic isolation barrier connecting, in a first case, the second negative electrode of the output capacitor to the positive input terminal of the primary side circuit or, in a second case, connecting the second positive electrode of the output capacitor to the negative input terminal...

  1. Decentralized Interleaving of Paralleled Dc-Dc Buck Converters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sinha, Mohit [University of Minnesota; Dhople, Sairaj [University of Minnesota; Poon, Jason [University of California at Berkeley

    2017-09-01

    We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.

  2. Active pre-filters for dc/dc Boost regulators

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2014-05-01

    Full Text Available This paper proposes an active pre-filter to mitigate the current harmonics generated by classical dc/dc Boost regulators, which generate current ripples proportional to the duty cycle. Therefore, high output voltage conditions, i.e., high voltage conversion ratios, produce high current harmonics that must be filtered to avoid damage or source losses. Traditionally, these current components are filtered using electrolytic capacitors, which introduce reliability problems because of their high failure rate. The solution introduced in this paper instead uses a dc/dc converter based on the parallel connection of the Boost canonical cells to filter the current ripples generated by the Boost regulator, improving the system reliability. This solution provides the additional benefits of improving the overall efficiency and the voltage conversion ratio. Finally, the solution is validated with simulations and experimental results.

  3. Linking DC together with TRSL

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth; Yong, X.

    2000-01-01

    in a method for real-time developments. An operational semantics with behavior is specified for TRSL. It is defined what its means for a TRSL process to satisfy a DC requirement, and a method for verifying whether the satisfaction relation holds or not is provided. Our contribution also demonstrates a general......Duration Calculus (DC) is an interval-based real-time logic, which can be used in capturing and eliciting users' real-time requirements. The Timed RAISE Specification Language (TRSL) is an extension of the RAISE Specification Language with real-time features. This paper links DC and TRSL together...

  4. DC Microgrids—Part II

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Lu, Xiaonan; Quintero, Juan Carlos Vasquez

    2016-01-01

    distribution applications such as traction, telecom, vehicular and distributed power systems can be classified under DC MG framework and ongoing development and expansion of the field is largely influenced by concepts used over there. This paper aims firstly to shed light on the practical design aspects of DC...... MG technology concerning typical power hardware topologies and their suitability for different emerging smart grid applications. Then, an overview of the state of the art in DC MG protection and grounding is provided. Owing to the fact that there is no zero current crossing, an arc that appears upon...

  5. DC-Compensated Current Transformer.

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-20

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component.

  6. DC injection into low voltage AC networks

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This report summarises the results of a study investigating the impact of levels of injected DC current injections on a low voltage AC distribution network systems in order to recommend acceptable limits of DC from microgeneration. Relevant literature is reviewed, and the impact of DC levels in distribution transformers, transformer modelling, and instrumental transformers are discussed. The impact of DC in residual current devices (RCD) and in domestic electricity watt hour meters is examined along with DC enhanced corrosion, corrosion failure, and the measurement of DC current injection. Sources of DC injection outlined include DC from computer power supplies, network faults, geomagnetic phenomena, lighting circuits/dimmers, and embedded generators.

  7. El sida y las personas mayores AIDS and the elderly

    Directory of Open Access Journals (Sweden)

    Alica Hanzeliková Pogrányivá

    2006-06-01

    Full Text Available Contraer y transmitir el VIH/sida es un riesgo real en cualquier etapa de la vida del hombre. Esta enfermedad tiene unas connotaciones concretas que pueden influir en diferentes áreas del individuo: psicológica, económica, social, familiar, etc., en cualquier edad, pero aún más si el afectado es una persona mayor. La falta de información sobre la enfermedad y su contagio en la vejez se puede convertir en una amenaza. El motivo de este trabajo es analizar la información y formación que se desprende de la bibliografía respecto a las personas mayores en materia de VIH/sida y proponer actuaciones que abarquen aspectos de prevención, promoción y cuidados.Catching or transmiting AIDS is a risk at any stage of people’s life. This disease has specific connotations that can influence different areas of the individual: psychological, economical, social, family life, etc., at any age but even more if the affected is an old person. The lack of information about the disease and its infection can turn out to be a serious menace. The motivation behind this work is to analize the information and education found in bibliographic sources, regarding old people and their relation to AIDS, and propose actions that embrace prevention, promotion and care aspects.

  8. Future electoral impacts of having a female mayor

    Directory of Open Access Journals (Sweden)

    Paulo Arvate

    2017-08-01

    Full Text Available We explore an electoral quasi-experiment where a woman nearly won or lost to a man in a mayoral election. Our data combines municipal Brazilian election results, which occur every four years, with municipal level votes for female and male candidates in state and federal deputy elections, whose districts are larger than the municipalities. Our results show that when voters are exposed to a female leader, the relative number of votes given to female candidates increases. This result depends on the political environment in which the exposure occurs. These effects on the electorate's response tend to be stronger: 01. in municipalities where there is a previous higher proportion of female councilors, and 02. when the mayors have higher education levels. Our results provide evidence that the observed electorate's gender preferences in politics are alterable, but that policy interventions aimed to equalize access will be more effective if they are targeted at underrepresented populations that have the correct skill requirements to perform in leadership positions.

  9. Dependencia funcional y bienestar en personas mayores institucionalizadas

    Directory of Open Access Journals (Sweden)

    María Teresa Rodríguez Díaz

    2014-06-01

    Full Text Available El presente estudio tiene como objetivo evaluar el bienestar emocional de las personas mayores de 60 años en relación al grado de dependencia funcional. Como indicadores del bienestar se evalúan los niveles de depresión (Yesavage y ansiedad (STAI-R, la satisfacción vital (CSV y la ansiedad ante la muerte (DAS. Se ha realizado un estudio descriptivo transversal en un grupo de personas mayores de 60 años (n=103. Los datos se han recogido usando cuestionarios estandarizados. Para el análisis de los datos se han utilizado correlaciones bivariadas entre las principales medidas, análisis univariado (ANOVA y la prueba de Bonferroni para comprobar las diferencias significativas entre los grupos (p< .05. Los resultados indican que se encuentran diferencias significativas entre los grupos de dependencia para la edad, deterioro cognitivo, depresión y ansiedad ante la muerte. En conclusión, se encuentra una relación directa entre el grado de dependencia funcional y el nivel de malestar emocional.

  10. Facebook Usage by Mayors in Central and Southeastern Europe

    Directory of Open Access Journals (Sweden)

    Milica Vučković

    2013-12-01

    Full Text Available The ever increasing rise of social media network users consequently leaves a mark on political communication. While social media tools are already adopted in political marketing, primarily in election campaigning, governments are still new in using social media. The aim of this study is to examine how Facebook is used by city mayors in countries of Central and Southeastern Europe in two months period, from March 1st to April 30th of 2012. Using content analysis we first analyzed status massages in order to see what kind of status messages they post: personal or political. Secondly, we conducted an analysis of comments on the examined statuses, in order to examine if citizens make constructive, cynical, supportive or neutral comments. We examined ten city mayors’ Facebook pages in five countries, Bulgaria, Croatia, Hungary, Macedonia and Slovenia. The results have revealed that city mayors in Central and Southeastern Europe use Facebook almost exclusively for official purposes. Secondly, the analysis of citizens’ comments demonstrates that expressing cynicism on Facebook is not the trend in these countries. The findings further confirm that Facebook is a good platform for gathering supporters, while there were no strong evidence found that it serves as platform for constructive discussion. The paper finally discusses how politician’s status messages can engage a larger number of citizens.

  11. La inflación de los adultos mayores en Colombia

    Directory of Open Access Journals (Sweden)

    Álvaro Montenegro

    2016-12-01

    Full Text Available Este artículo compara el comportamiento de la inflación para el hogar promedio y diversos tipos de hogares de adultos mayores en Colombia. Los resultados indican que, en promedio, los adultos mayores gastan una mayor proporción de su ingreso en vivienda y salud y una menor proporción en educación, y que experimentaron una mayor inflación que la población en general entre diciembre de 2008 y mayo de 2015. Los hogares de adultos mayores más pobres gastan una mayor proporción en vivienda y alimentación, y para estos la inflación fue mayor que para los de adultos mayores de altos ingresos.

  12. Borehole DC-12 hydrostratigraphic chart

    International Nuclear Information System (INIS)

    Gephart, R.E.

    1981-09-01

    This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-12. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

  13. Borehole DC-14 hydrostratigraphic chart

    International Nuclear Information System (INIS)

    Gephart, R.E.

    1981-09-01

    This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-14. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

  14. Borehole DC-15 hydrostratigraphic chart

    International Nuclear Information System (INIS)

    Gephart, R.E.

    1981-09-01

    This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-15. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

  15. Mayor's Firm Hand over N.Y.C. Schools Sparks New Debate

    Science.gov (United States)

    Archer, Jeff

    2004-01-01

    This article reports a new debate on mayoral control over New York City schools. Mayoral control of the N.Y.C. schools was at the center of renewed debate, after Mayor Michael R. Bloomberg replaced two members of the city's education policymaking board to ensure enough votes for a controversial plan he backed to end social promotion. The shakeup…

  16. Well coupled, low noise, dc SQUIDS

    International Nuclear Information System (INIS)

    Muhlfelder, B.; Beall, J.A.; Cromar, M.W.; Johnson, W.W.; Ono, R.H.

    1985-01-01

    The authors have designed, fabricated, and tested a Double Transformer (DT) coupled dc SQUID (Superconducting Quantum Interference Device) with low noise, an input inductance of 1μH and a smooth input-output characteristic. A transmission line model is presented to explain a resonance in the input-output characteristic of early versions of this device. Guided by the results of numerical simulations a new version of this device has been built and tested. Experimental results are presented that show that the resonance can be moved to a higher voltage by reducing the area of the SQUID loop. The voltage-external flux characteristic of some of these new devices agrees to within 10% with computer simulations. The minimum detectable energy per unit bandwidth (MDE) referred to the SQUID loop, is 10h, where h is Planck's constant. Computer simulations indicate an MDE of 6h

  17. El adulto mayor en cirugía general

    Directory of Open Access Journals (Sweden)

    Armando Quintana Proenza

    2001-12-01

    Full Text Available Se realizó un estudio descriptivo y transversal con 249 pacientes de 60 y más años de edad operados en el Servicio de Cirugía General de los hospitales Clinicoquirúrgico Docente "Amalia Simoni" y General Docente "Martín Chang Puga" de la provincia Camagüey en un bienio. Más de la mitad de los pacientes tenían entre 60 y 69 años de edad, con predominio del sexo masculino, en una relación de 1,9:1. El mayor número de cirugía de urgencia se realizó en personas mayores de 70 años. La hernia de la pared abdominal fue el diagnóstico operatorio más frecuente (49 %. La hipertensión arterial constituyó la enfermedad asociada de mayor relevancia. La sepsis predominó entre las complicaciones posoperatorias. La mortalidad global fue de 16,87 %. Más del 70 % de los pacientes pudo haber sido operado en edades más tempranas de la vida de haber recibido una orientación médica adecuada.A descriptive cross-sectional study was conducted among 249 patients aged 60 and over that were operated on at the Service of General Surgery of "Amalia Simoni" Clinical and Surgical Teaching Hospital and "Martín Chang Puga" General Teaching Hospital, in the province of Camagüey, in a biennium. More than half of the patients were aged 60-69, with predominance of males in a ratio 1.9:1.The highest number of emergency surgery was performed in individuals over 70. The hernia of the abdominal wall was the most frequent surgical diagnosis (49 %. Arterial hypertension was the most important associated disease. Sepsis prevailed among the postoperative complications. Total mortality was 16.87 %. More than 70 % of the patients could have been operated when they were younger if they had received an adequate medical guidance.

  18. Five-Level Active-Neutral-Point-Clamped DC/DC Converter for Medium-Voltage DC Grids

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Chen, Zhe

    2017-01-01

    This paper proposes a five-level active-neutralpoint- clamped (5L-ANPC) dc/dc converter for applications in medium voltage dc (MVDC) grids. A modulation strategy is proposed for the 5L-ANPC dc/dc converter to generate multilevel voltage waveforms, which can effectively reduce voltage change rate dv...... effectively eliminate high voltage leaps caused by the dead time effect. In addition, a capacitor voltage control strategy is proposed for the 5L-ANPC dc/dc converter to ensure the balanced flying capacitor voltage and desired five-level voltage waveforms. Finally, simulation and experimental studies...

  19. Vida y salud con la gimnasia para adultos mayores

    Directory of Open Access Journals (Sweden)

    MSc. María Magdalena Rosado Álvarez

    2018-01-01

    Full Text Available El objetivo del trabajo es realizar una revisión metódica de las normas vigentes en la constitución de la República del Ecuador, el impacto de la gimnasia para disfrutar una vida saludable los adultos mayores el periodo mayo a septiembre de 2016. La investigación tuvo un enfoque cuantitativo, de alcance explicativo, con diseño experimental de tipo pre experimental con corte longitudinal, a través de una muestra de 20 pacientes, donde se implementó métodos para la recolección de datos demostrando su consistencia, tales como: historia clínica, encuesta, test de Tinetti, prueba de Romberg. Los resultados reflejan mejoría a la marcha y equilibrio pasando de un 15% a 10% de la población

  20. Actitud y miedo ante la muerte en adultos mayores

    Directory of Open Access Journals (Sweden)

    Ana Fernanda Uribe Rodríguez

    2007-01-01

    Full Text Available A través de los años el tema de la muerte se ha conceptualizado de diversas maneras. En la actualidad las personas evitan hablar del tema y se observa conductas evitativas, de miedo y ansiedad. El presente artículo tiene como objetivo evaluar la actitud y miedo ante la muerte en una muestra de 170 adultos mayores ( X :71,02; DT=5,946 de la ciudad de Cali-Colombia por medio del Perfil Revisado de Actitudes hacia la Muerte (PAM-R y la Escala de Collet-Lester (1969; se tuvo en cuenta las variables sexo, religión y estrato socioeconómico. Los resultados muestran diferencias significativas en función del sexo en las escalas de miedo a la propia muerte, evitación de la muerte, aceptación de acercamiento. Con relación al estrato socioeconómico se encontraron diferencias significativas en las escalas de miedo a la muerte y aceptación de acercamiento y en función de la religión sólo hay diferencias significativas en la evitación a la muerte. Se concluye la importancia de contribuir desde la psicología, al mejoramiento en los procesos de adaptación a los duelos y disminuir la presencia de duelos patológicos que se generan ante situaciones inesperadas y mal elaboradas en este caso, en los adultos mayores.

  1. Estudio descriptivo de algunas variables emocionales en las personas mayores

    Directory of Open Access Journals (Sweden)

    Igone Etxeberria

    2016-08-01

    Full Text Available Se analizó el funcionamiento emocional (afecto positivo y negativo, satisfacción con la vida, soledad y estrategias de regulación de las personas centenarias en comparación con el de personas de menor edad (65-74, 75-84 y 85-94 años. Participaron en el estudio 257 personas mayores sin deterioro cognitivo y sin dependencia para las Actividades de la Vida Diaria (AVD. Los resultados revelaron que, en las personas centenarias, se producía una disminución de la afectividad positiva en comparación con los grupos de 65 a 74 años y de 75 a 84 años, pero no así con el de 85 a 94 años. Además, presentaban menor afecto negativo y más satisfacción con la vida (en comparación con el grupo de 65 a 74 años, al tiempo que manifestaban sentirse más solas (en comparación con los grupos de 65 a 74 años y de 75 a 84 años. Con respecto a las estrategias de regulación, en general, las personas centenarias utilizan en menor medida las estrategias proactivas y la solución de problemas y en mayor medida las pasivas, al menos en la regulación de la tristeza. En conclusión, a pesar de experimentar menos afecto positivo y más soledad se produce cierta disminución en el afecto negativo, e incluso cierto aumento de la satisfacción con la vida. En lo que respecta a la regulación emocional, las personas centenarias utilizan menos las estrategias proactivas y más las pasivas (tristeza.

  2. 75 FR 63040 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-30, DC...

    Science.gov (United States)

    2010-10-14

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10... following new airworthiness directive (AD): 2010-21-13 McDonnell Douglas Corporation: Amendment 39-16473... November 18, 2010. Affected ADs (b) None. Applicability (c) This AD applies to McDonnell Douglas...

  3. 75 FR 68246 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-11-05

    ...-1044; Directorate Identifier 2010-NM-033-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas..., 2007) and adding the following new AD: McDonnell Douglas Corporation: Docket No. FAA-2010-1044.... Applicability (c) This AD applies to all McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

  4. Percepción del estudiante de medicina de una universidad pública acerca del docente adulto mayor y del adulto mayor en general

    Directory of Open Access Journals (Sweden)

    Martha Martina

    2014-07-01

    Full Text Available Introducción: La mayoría de los estudios disponibles muestran que las imágenes que construyen los jóvenes sobre la vejez, en general, se asocian a una valoración negativa de esta etapa de la vida. Objetivos: Analizar la percepción de los estudiantes de Medicina Humana de la UNMSM acerca de la vejez, así como la existencia o no de estereotipos negativos acerca de la vejez y del docente adulto mayor. Diseño: Estudio transversal. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Participantes: Estudiantes del primero, tercero y quinto año de la Escuela Académico Profesional de Medicina Humana. Intervenciones: Aplicación de una escala de diferencial semántico para medir la percepción de los estudiantes mediante un cuestionario autoadministrado. Principales medidas de resultados: De una muestra de 319 estudiantes, 54,2% fue del sexo masculino y el promedio de edad 21,7±2,6 años; 90,3% tuvo cercanía con profesores mayores de 70 años. Los alumnos del quinto año otorgaron menores puntuaciones a los docentes adultos mayores (p=0,003 y a los adultos mayores en general (p=0,045. Los estudiantes que en su familia convivían con personas mayores de 70 años tuvieron una percepción más positiva sobre los adultos mayores en general (p=0,037. Respecto a la percepción de los estudiantes acerca del docente adulto mayor destacaron cinco características que superaron el 70% del puntaje, tipificándolo como seguro de sí mismo (78%, organizado (73,9%, interesado en el aprendizaje del estudiante (72,8%, planificador (72,6% y emocionalmente estable (71,8%. Respecto al adulto mayor, los puntajes no superaron el 70%, y en general lo tipificaron como tratable, sociable y hábil. Conclusiones: Los estudiantes de medicina mostraron una percepción positiva hacia el docente adulto mayor y sobre el adulto mayor en general. Existieron diferencias estadísticamente significativas según el año de estudios. Los

  5. Pulsewidth modulated DC-to-DC power conversion circuits, dynamics, and control designs

    CERN Document Server

    Choi, Byungcho

    2013-01-01

    This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to

  6. Atmel Microcontroller Based Soft Switched PWM ZVS Full Bridge DC to DC Converter

    Directory of Open Access Journals (Sweden)

    DEEPAK KUMAR NAYAK

    2010-12-01

    Full Text Available This paper deals with the simulation and implementation of soft switched PWM ZVS full bridge DC to DC converter. The 48V DC is efficiently reduced to 12V DC using a DC to DC converter. This converter has advantages like reduced switching losses, stresses and EMI. Input DC is converted into high frequency AC and it is stepped down to 12V level. Later it is rectified using a full wave rectifier. Laboratory model of microcontroller based DC to DC converter is fabricated and tested. The experimental results are compared with the simulation results.

  7. 75 FR 60602 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-10-01

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10... adding the following new AD: 2010-20-14 McDonnell Douglas Corporation: Amendment 39-16449. Docket No. FAA... the airplanes identified in paragraphs (c)(1) and (c)(2) of this AD. (1) McDonnell Douglas Corporation...

  8. 75 FR 6160 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-02-08

    ...-0032; Directorate Identifier 2009-NM-213-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas...: McDonnell Douglas Corporation: Docket No. FAA-2010-0032; Directorate Identifier 2009-NM-213-AD. Comments Due... applies to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A...

  9. 75 FR 38943 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-30, DC...

    Science.gov (United States)

    2010-07-07

    ...-0672; Directorate Identifier 2010-NM-047-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas...: McDonnell Douglas Corporation: Docket No. FAA-2010-0672; Directorate Identifier 2010-NM-047-AD. Comments Due... applies to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10), DC-10...

  10. Light-weight DC to very high voltage DC converter

    Science.gov (United States)

    Druce, R.L.; Kirbie, H.C.; Newton, M.A.

    1998-06-30

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

  11. Light-weight DC to very high voltage DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)

    1998-01-01

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

  12. Radiated electromagnetic emissions of DC-DC converters

    International Nuclear Information System (INIS)

    Feld, L; Jussen, R; Karpinski, W; Klein, K; Sammet, J; Wlochal, M

    2010-01-01

    For the CMS tracker at SLHC a new powering scheme is considered to be mandatory to allow the detector to provide at least the same performance as today at the LHC. The baseline solution of CMS foresees the use of DC-DC converters to provide larger currents with smaller losses. An important component of most converters are inductors which, however, tend to radiate the switching noise generated by the converter. The emissions of different inductors have been measured and simulated, the coil design has been optimized and noise susceptibility measurements, with present CMS hardware, have been performed. This article summarizes the results.

  13. Pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2008-01-01

    This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

  14. DESIGN OPTIMIZATION OF RESONANT DC-DC CONVERTERS

    OpenAIRE

    Belqasem Aljafari

    2016-01-01

    Resonant DC/DC converters are the class of converters, which have L-C resonant tank serving as a major part of the power conversion process. The fundamental concept of the resonant converter is that the circulating energy in an L-C resonant circuit is manageable by changing the operating frequency, and therefore the converter can condition the input power to the desired output voltage. The development in power conversion technology is steady demand for high power efficiency and high power den...

  15. Repercusión de la formación en adultos mayores: El caso del Aula Abierta de Mayores

    Directory of Open Access Journals (Sweden)

    José Luis Rodríguez Díez

    2015-05-01

    Full Text Available En esta Tesis se hace hincapié en la importancia del envejecimiento activo y la influencia del aprendizaje a lo largo de la vida en el mismo. La investigación que hemos realizado analiza en qué medida la asistencia al programa universitario para mayores denominado “Aula Abierta de Mayores” y ofertado por la Universidad Pablo de Olavide de Sevilla (España, influye en una visión más satisfactoria de la vida, su capacidad de aprendizaje y la modificación de hábitos familiares. Se ha utilizado un método mixto. Se ha realizado una encuesta a 105 sujetos y los resultados demuestran cómo la asistencia a este programa de formación les ha cambiado la vida en cada una de las variables estudiadas.

  16. DC grid for home applications

    Science.gov (United States)

    Elangovan, D.; Archana, R.; Jayadeep, V. J.; Nithin, M.; Arunkumar, G.

    2017-11-01

    More than fifty percent Indian population do not have access to electricity in daily lives. The distance between the power generating stations and the distribution centers forms one of the main reasons for lack of electrification in rural and remote areas. Here lies the importance of decentralization of power generation through renewable energy resources. In the present world, electricity is predominantly powered by alternating current, but most day to day devices like LED lamps, computers and electrical vehicles, all run on DC power. By directly supplying DC to these loads, the number of power conversion stages was reduced, and overall system efficiency increases. Replacing existing AC network with DC is a humongous task, but with power electronic techniques, this project intends to implement DC grid at a household level in remote and rural areas. Proposed work was designed and simulated successfully for various loads amounting to 250 W through appropriate power electronic convertors. Maximum utilization of the renewable sources for domestic and commercial application was achieved with the proposed DC topology.

  17. Linking DC together with TRSL

    DEFF Research Database (Denmark)

    Haxthausen, Anne; Yong, Xia

    1999-01-01

    In this talk we present a method for linking the Duration Calculus together with the Timed RAISE Specification Language. Duration Calculus (DC) [ZHR91] is an interval-based real time logic, which can be used naturally in capturing and eliciting users' real time requirements in the form of constra......In this talk we present a method for linking the Duration Calculus together with the Timed RAISE Specification Language. Duration Calculus (DC) [ZHR91] is an interval-based real time logic, which can be used naturally in capturing and eliciting users' real time requirements in the form.......TRSL is a real-time extension of the RAISE Specification Language (RSL) [Rlg92] which together with its associated method [Rmg95]and tools has shown to be very useful in the industrial development of software systems. Therefore, a promising approach for the development of real-time systemscould be to use DC...... for high-level specifications of real-time requirementsand TRSL for specifying real-time implementations in the form of timed communicating concurrent processes.In order to link DC and TRSL together in a well-founded way, we formally define what it means for a TRSL process to satisfy a DC requirement...

  18. Beneficios percibidos por adultos mayores incorporados al ejercicio

    Directory of Open Access Journals (Sweden)

    René Barrios Duarte

    2003-04-01

    Full Text Available El propósito del trabajo es conocer los beneficios que perciben los adultos mayores del sexo femenino, con larga permanencia en el ejercicio, y las relaciones que se establecen entre estos y las variables edad, nivel cultural, tiempo de permanencia y ocupación anterior. Se tomó una muestra de 75 personas pertenecientes a 5 círculos de abuelos de Ciudad de La Habana, con edades entre 56 y 90 años, a los cuales se les aplicó un cuestionario de datos sociodemográficos y una entrevista. Los beneficios percibidos se agruparon en 4 categorías principales: salud, aptitud, psicológicos y sociales. No se encontró relación de dependencia con ninguna de las variables analizadas, aunque sí se encontraron diferencias en categorías específicas. El estudio detalla los beneficios que se pueden percibir con la práctica sistemática en programas destinados al adulto mayor, así como su carácter multidimensional, físico, psicológico y social. Se confirma la importancia del ejercicio y se ofrecen razones para su fomento.The objective of the paper is to find out the benefits that older females receive from practicing exercises for a long time and the relations that are established between these benefits and the variables age, educational level, length of practice and former occupation. A sample of 75 persons from 5 grandfather´s clubs in the City of Havana, aged 56-60 years was administered a socio-demographic questionnaire and an interview. Received benefits were grouped into 4 main categories: health, aptitude, psychological and social. There was no dependence relation with any of the analyzed variables, although differences were found in specific categories. The study detailed the benefits that may be received from systematic physical exercising in programs devoted to older people as well as their multidimensional, physical, psychological and social character. The paper confirmed the importance of exercising and provided reasons for encouraging

  19. Capacidad funcional y salud: orientaciones para cuidar al adulto mayor

    Directory of Open Access Journals (Sweden)

    CLARA INÉS GIRALDO M

    2008-07-01

    Full Text Available Objetivo: valorar la salud y la capacidad funcional de ancianos con dependencia funcional para el autocuidado, como elementos para orientar el cuidado de enfermería y el cuidado familiar en casa. Metodología: estudio descriptivo transversal en 40 personas de 65 y más años con dependencia funcional, cuidados por familiar, en Envigado Colombia; muestreo por conveniencia. Valoración de la capacidad funcional con el índice de Katz y la escala de Lawton y Brody, ajustados según grupo de Neurociencias, Universidad de Antioquia. Hallazgos: población entre 67 y 98 años, edad promedio 84,08 años; 82,5% mujeres. Sistemas orgánicos más afectados: cardiovascular, osteomuscular y neurológico; entre 47,5% y 27,5% de los ancianos los tenían comprometidos. Se identificaron dos comportamientos: los hombres, y las personas de edad más avanzada, con mayores grados de dependencia en las actividades básicas e instrumentales; no se determinó asociación estadística por el pequeño tamaño muestral. Las actividades básicas estaban afectadas así: entre el 67,5% y el 55% de los ancianos requería ayuda; y las actividades instrumentales estuvieron comprometidas: entre el 95% y el 75% de los ancianos son totalmente dependientes en ellas. Conclusiones: Enfermería ha de considerar la valoración de la capacidad funcional articulada al estado de salud integral de los ancianos, para orientar su cuidado y apoyar a los cuida-dores familiares. Esto además previene dependencias de cuidado innecesarias que estarían en contra de las aspiraciones del adulto mayor como individuo autónomo e independiente. Es tarea de profesionales en enfermería capacitar a cuidadores familiares sobre valoración de la capacidad funcional.

  20. Modeling and analysis of fractional order DC-DC converter.

    Science.gov (United States)

    Radwan, Ahmed G; Emira, Ahmed A; AbdelAty, Amr M; Azar, Ahmad Taher

    2017-07-11

    Due to the non-idealities of commercial inductors, the demand for a better model that accurately describe their dynamic response is elevated. So, the fractional order models of Buck, Boost and Buck-Boost DC-DC converters are presented in this paper. The detailed analysis is made for the two most common modes of converter operation: Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM). Closed form time domain expressions are derived for inductor currents, voltage gain, average current, conduction time and power efficiency where the effect of the fractional order inductor is found to be strongly present. For example, the peak inductor current at steady state increases with decreasing the inductor order. Advanced Design Systems (ADS) circuit simulations are used to verify the derived formulas, where the fractional order inductor is simulated using Valsa Constant Phase Element (CPE) approximation and Generalized Impedance Converter (GIC). Different simulation results are introduced with good matching to the theoretical formulas for the three DC-DC converter topologies under different fractional orders. A comprehensive comparison with the recently published literature is presented to show the advantages and disadvantages of each approach. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  1. An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications

    Directory of Open Access Journals (Sweden)

    Liwen Pan

    2016-06-01

    Full Text Available This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs. The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for motor drive system and battery-charging system with a power pulsation reduction circuit. Simulation results in MATLAB/Simulink and experiments on a 30-kW motor drive and 3.3-kW AC/DC charging prototype validate the performance of the proposed technology. In addition, power losses, efficiency comparison and thermal stress for the integrated charger are illustrated. The results of the analyses show the validity of the advanced integrated charger for electric vehicles.

  2. Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

    Science.gov (United States)

    Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

    2014-09-09

    A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

  3. Application of Distributed DC/DC Electronics in Photovoltaic Systems

    Science.gov (United States)

    Kabala, Michael

    In a typical residential, commercial or utility grade photovoltaic (PV) system, PV modules are connected in series and in parallel to form an array that is connected to a standard DC/AC inverter, which is then connected directly to the grid. This type of standard installation; however, does very little to maximize the energy output of the solar array if certain conditions exist. These conditions could include age, temperature, irradiance and other factors that can cause mismatch between PV modules in an array that severely cripple the output power of the system. Since PV modules are typically connected in series to form a string, the output of the entire string is limited by the efficiency of the weakest module. With PV module efficiencies already relatively low, it is critical to extract the maximum power out of each module in order to make solar energy an economically viable competitor to oil and gas. Module level DC/DC electronics with maximum power point (MPP) tracking solves this issue by decoupling each module from the string in order for the module to operate independently of the geometry and complexity of the surrounding system. This allows each PV module to work at its maximum power point by transferring the maximum power the module is able to deliver directly to the load by either boosting (stepping up) the voltage or bucking (stepping down) the voltage. The goal of this thesis is to discuss the development of a per-module DC/DC converter in order to maximize the energy output of a PV module and reduce the overall cost of the system by increasing the energy harvest.

  4. Paleointensities on 8 ka obsidian from Mayor Island, New Zealand

    Directory of Open Access Journals (Sweden)

    A. Ferk

    2011-11-01

    Full Text Available The 8 ka BP (6050 BCE pantelleritic obsidian flow on Mayor Island, Bay of Plenty, New Zealand, has been investigated using 30 samples from two sites. Due to a very high paramagnetic/ferromagnetic ratio, it was not possible to determine the remanence carriers. This is despite the fact that the samples were studied intensively at low, room, and high temperatures. We infer that a stable remanence within the samples is carried by single- or close to single-domain particles. Experiments to determine the anisotropy of thermoremanence tensor and the dependency on cooling rate were hampered due to alteration resulting from the repeated heating of the samples to temperatures just below the glass transition. Nonetheless, a well-defined mean paleointensity of 57.0 ± 1.0 μT, based on individual high quality paleointensity determinations, was obtained. This field value compares very well to a paleointensity of 58.1 ± 2.9 μT, which Tanaka et al. (2009 obtained for 5500 BCE at a site 100 km distant. Agreement with geomagnetic field models, however, is poor. Thus, gathering more high-quality paleointensity data for the Pacific region and for the southern hemisphere in general to better constrain global field models is very important.

  5. El entorno residencial de los mayores en Madrid

    Directory of Open Access Journals (Sweden)

    Fernández-Mayoralas Fernández, Gloria

    2002-12-01

    Full Text Available The aim of this paper is to study the residential environment and its perception by the elderly people ageing in place in Madrid, to obtain a better knowledge of the elements to modify in order to increase their satisfaction. The Censo de Población y Vivienda (1991 and the Survey Ageing in Place (1998 are used. In general terms, old people live in old houses, as owners, not crowded but with lack of facilities. These people have been living for a long time in the same neighbourhood, an environment affected by the problems characteristic of big cities, and are integrated in the neighbour by means of activities requiring not to much physical or financial effort. Residential lacks affect mainly to that groups with social and economic vulnerability: female, lower income and educational level, worse health status,... So, two out ten aged people would move mainly due to the negative conditions of habitability, adaptation and facilities. Moreover, reasons for not moving are related to the force of habit, the memories, or consequence of age, bad health or less resources.

    [es] El entorno residencial de los mayores en Madrid. El objetivo de este artículo es estudiar el ámbito residencial de los mayores que envejecen en su casa y la percepción que tienen sobre este medio, para obtener un mejor conocimiento de los aspectos que deberían modificarse a fin de incrementar su satisfacción. Las fuentes utilizadas son el Censo de Población y Vivienda de 1991 y la Encuesta Envejecer en Casa de 1998. A grandes rasgos, los viejos madrileños viven en casas viejas, de las que son propietarios, sin problemas de hacinamiento pero con carencias dotacionales. Durante la mayor parte de su vida adulta han residido en el mismo barrio, un entorno que actualmente está afectado por los problemas propios de las grandes ciudades, y en el que se integran socialmente mediante actividades que no requieren demasiado esfuerzo físico o monetario. Las deficiencias

  6. Maltrato institucional a adultos mayores Institutional elder abuse

    Directory of Open Access Journals (Sweden)

    Miriam Rubio Acuña

    2012-12-01

    Full Text Available El maltrato institucional se refiere a cualquier forma de abuso que ocurre en servicios dirigidos a los ancianos. Esta revisión bibliográfica muestra que el maltrato se presenta con mayor frecuencia en residencias de larga estadía y el tipo más frecuente es la negligencia. Los factores asociados son los que tienen relación con el residente y con el ambiente. Las principales estrategias son invertir recursos sociosanitarios, sensibilizar a la población respecto al maltrato de los ancianos, considerar las necesidades de estos, fortalecer la formación de pregrado de los profesionales de salud en este ámbito y realizar educación continua. El maltrato es un problema social que debe ser abordado de manera integral.Institutional abuse refers to any form of abuse that occurs in services for the elderly. This literature review indicates that abuse occurs more frequently in nursing homes and the most frequent type of neglect. The factors that may relate to the relationship with the resident and the environment. The main strategies relate to social and health invest resources, raising awareness about the abuse of the elderly, consider their needs, strengthen undergraduate education of health professionals in this field and make continuing education. Abuse is a social problem so this must be addressed holistically.

  7. Voltage Weak DC Distribution Grids

    NARCIS (Netherlands)

    Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.

    2017-01-01

    This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of

  8. Compact integrated dc SQUID gradiometer

    Science.gov (United States)

    de Waal, V. J.; Klapwijk, T. M.

    1982-10-01

    An all-niobium integrated system of first-order gradiometer and dc suprconducting quantum interference device (SQUID) has been developed. It is relatively simple to fabricate, has an overall size of 17×12 mm and a sensitivity of 3.5×10-12 T m-1 Hz-1/2.

  9. Compact integrated dc SQUID gradiometer

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, V.J.; Klapwijk, T.M.

    1982-10-01

    An all-niobium integrated system of first-order gradiometer and dc suprconducting quantum interference device (SQUID) has been developed. It is relatively simple to fabricate, has an overall size of 17 x 12 mm and a sensitivity of 3.5 x 10/sup -12/ T m/sup -1/ Hz/sup -1/2/.

  10. Experiments with a DC Motor

    Science.gov (United States)

    Kraftmakher, Yaakov

    2010-01-01

    Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the…

  11. Borehole DC-6 hydrostratigraphic chart

    International Nuclear Information System (INIS)

    Gephart, R.E.

    1981-09-01

    This hydrostratigraphic chart for Borehole DC-6 identifies the basic stratigraphy and preliminary hydrologic test results. This borehole was cored for obtaining stratigraphic data and only that portion within the Grande Ronde formation remains open for hydrologic testing. The upper two formations were cased and cemented off

  12. DC motor operation controlled from a DC/DC power converter in pulse mode with low duty cycle

    OpenAIRE

    Stefanov, Goce; Kukuseva, Maja; Citkuseva Dimitrovska, Biljana

    2016-01-01

    In this paper pulse mode of operation of DC motor controlled by DC/DC power converter is analyzed. DC motor operation with time intervals in which the motor operates without output load is of interest. In this mode it is possible the motor to restore energy. Also, in the paper are represented calculations for the amount of the restored energy in the pulse mode operation of the motor for different duty cycles.

  13. Residencia para personas mayores en Villa del Prado, Madrid

    Directory of Open Access Journals (Sweden)

    García-Vaquero Alvaro, Javier

    2003-12-01

    Full Text Available Basic faci lities fo r socia l serv ices. Building designed as a home fo r the elderly, with 120 beds plus adult day care service for 40 seniors; erected under an agreement between the Madrid Housing Institute (IVIMA and the Regional Department ofFamily Affairs and Social Services in a small tOWlI in the region ofMadrid with a population of4.350. The design lends particular auention to zoning and spatial distribution based 0 11 a specific organisational chart as wel! as to daylight-related questions. The choice ofmaterials and colours is in keeping with the intended use ofthe building and the characteristics ofits users.Equipamiento Básico para Asistencia Social. Edificio destinado a Residencia pa ra Personas Mayores con una capacidad para 120 plazas residenciales con Centro de Estancias Diurnas para 40 plazas externas, realizado mediante Convenio entre el Instituto de la Vivienda de Madrid (IVIMA y la Consejeria de Familia y Servicios Sociales de la Comunidad de Madrid, en un pequeño municipio de esta Comunidad con una población de 4.350 habitantes. El proyecto dedica especial atención a la zonificación y a la distribució n espacial, en fu nci án de IIt I claro organigrama, y al manej o de la luz natural. La elección de materiales y colores se realiza en funci án del uso a que se destina el edificio ya las especiales características de sus usuarios.

  14. Caracterización de la familia del adulto mayor

    Directory of Open Access Journals (Sweden)

    Yahima Limia Núñez

    2014-08-01

    Full Text Available El envejecimiento en la familia constituye un problema mundial y nacional, teniendo en cuenta esa premisa se realizó un estudio de tipo descriptivo, con el uso de técnicas cuantitativas y cualitativas, para caracterizar las familias donde viven adultos mayores, pertenecientes al área de salud del policlínico docente Dr. Gustavo Aldereguía Lima. Se seleccionaron al azar diez familias del área incluida en el consultorio médico de la familia 94-01 que cumplieran con los criterios de inclusión, las que se caracterizaron a través de las variables socio-psicológicas: estructura, crisis, funcionamiento y percepción familiar; los datos se obtuvieron a partir de las técnicas de entrevista a la familia, la prueba de percepción de funcionamiento familiar (FF-SIL y la prueba de percepción de las relaciones familiares. En las familias estudiadas predominó la existencia de una estructura pequeña; nuclear y unigeneracional; multigeneracional. Las funciones que mejor cumplieron las familias fueron la económica y la educativo-cultural; y las crisis normativas que predominaron fueron la jubilación, el envejecimiento y la enfermedad. El funcionamiento familiar que prevaleció fue el funcional; los indicadores más afectados fueron los roles, la permeabilidad, la comunicación y la adaptabilidad; en la percepción familiar predominaron las familias armónicas, seguidas de las poco armónicas. Los indicadores más afectados fueron el sistema de apoyo, la comunicación y el desempeño de roles. Se concluyó que las familias presentaron fundamentalmente una estructura pequeña y nuclear, son funcionales y son armónicas

  15. Could US mayors achieve the entire US Paris climate target?

    Science.gov (United States)

    Gurney, K. R.; Huang, J.; Hutchins, M.; Liang, J.

    2017-12-01

    After the recent US Federal Administration announcement not to adhere to the Paris Accords, 359 mayors (and counting) in the US pledged to maintain their commitments, reducing emissions within their jurisdictions by 26-28% from their 2005 levels by the year 2025. While important, this leaves a large portion of the US landscape, and a large amount of US emissions, outside of the Paris commitment. With Federal US policy looking unlikely to change, could additional effort by US cities overcome the gap in national policy and achieve the equivalent US national Paris commitment? How many cities would be required and how deep would reductions need to be? Up until now, this question could not be reliably resolved due to lack of data at the urban scale. Here, we answer this question with new data - the Vulcan V3.0 FFCO2 emissions data product - through examination of the total US energy related CO2 emissions from cities. We find that the top 500 urban areas in the US could meet the national US commitment to the Paris Accords with a reduction of roughly 30% below their 2015 levels by the year 2025. This is driven by the share of US emissions emanating from cities, particularly the largest cohort. Indeed, as the number of urban areas taking on CO2 reduction targets grows, the less the reduction burden on any individual city. In this presentation, we provide an analysis of US urban CO2 emissions and US climate policy, accounting for varying definitions of urban areas, emitting sectors and the tradeoff between the number of policy-active cities and the CO2 reduction burden.

  16. BIENESTAR PSICOLÓGICO: ADULTOS MAYORES ACTIVOS A TRAVÉS DEL VOLUNTARIADO

    OpenAIRE

    FERRADA MUNDACA,LESLIE; ZAVALA GUTIÉRREZ,MERCEDES

    2014-01-01

    Objetivo: Comparar el nivel de bienestar psicológico de adultos mayores voluntarios del programa "Asesores Seniors" del Servicio Nacional del Adulto Mayor, Región del Bío-Bío, Chile, y adultos mayores no voluntarios, usuarios de un Centro de Salud Familiar de la misma región. Material y método: Corresponde a un estudio descriptivo - comparativo. La población del estudio corresponde a 60 adultos mayores, 30 voluntarios en un programa gubernamental y 30 no voluntarios usuarios de un Centro de S...

  17. DC to DC power converters and methods of controlling the same

    Science.gov (United States)

    Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

    2012-12-11

    A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

  18. A Study of Two Multi-Element Resonant DC-DC Topologies with Loss Distribution Analyses

    Directory of Open Access Journals (Sweden)

    Yifeng Wang

    2017-09-01

    Full Text Available In this paper, two multi-element resonant DC-DC converters are analyzed in detail. Since their resonant tanks have multiple resonant components, the converters display different resonant characteristics within different operating frequency ranges. Through appropriate design, both of the two proposed converters successfully lower the conversion losses and, meanwhile, broaden the voltage gain ranges as well: one converter is able to take full usage of the third order harmonic to deliver the active power, and thus the effective utilization rate of the resonant current is elevated; while the another minimizes the entire switching losses for power switching devices by restricting the input impedance angle of the resonant tank. Besides, the loss distribution is analyzed for the purpose of guiding the component design. In the end, two 500 W prototypes are fabricated to test the theoretical analyses. The results demonstrate that the two proposed converters can achieve wide voltage gain with the small frequency deviation, which noticeably contributes to highly efficient conversion. Their peak efficiencies are measured as 95.4% and 95.3%, respectively.

  19. Analysis of a high power, resonant DC-DC converter for DC wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

    2018-01-01

    This paper is introducing a new method of operation for a series resonant converter, with intended application in megawatt high-voltage DC wind turbines. Compared to a frequency controlled series resonant converter operated in sub resonant mode, the method (entitled pulse removal technique) allows...

  20. Dilation and Curettage (D&C)

    Science.gov (United States)

    ... For Patients About ACOG Dilation and Curettage (D&C) Home For Patients Search FAQs Dilation and Curettage ( ... February 2016 PDF Format Dilation and Curettage (D&C) Special Procedures What is dilation and curettage (D& ...

  1. Hierarchical Power Sharing Control in DC Microgrids

    DEFF Research Database (Denmark)

    Peyghami, Saeed; Mokhtari, Hossein; Blaabjerg, Frede

    2016-01-01

    Because of the advances in power electronics, DC-based power systems, have been used in industrial applications such as data centers [18], space applications [10], aircraft [12], offshore wind farms, electric vehicles [56], DC home systems [5, 20], and high-voltage DC transmission systems...

  2. Characterising and modelling extended conducted electromagnetic interference in densely packed DC-DC converter

    CSIR Research Space (South Africa)

    Grobler, Inus

    2013-09-01

    Full Text Available . The military specified DC-DC converters are applicable, spanning from 100 W handheld power managers up to 2 kW DC-DC battery chargers. Circuit layout high frequency effects as well as high frequency impedances of the power components were characterised...

  3. Full wave dc-to-dc converter using energy storage transformers

    Science.gov (United States)

    Moore, E. T.; Wilson, T. G.

    1969-01-01

    Full wave dc-to-dc converter, for an ion thrustor, uses energy storage transformers to provide a method of dc-to-dc conversion and regulation. The converter has a high degree of physical simplicity, is lightweight and has high efficiency.

  4. A DC-DC Conversion Powering Scheme for the CMS Phase-1 Pixel Upgrade

    CERN Document Server

    Feld, Lutz Werner; Marcel Friedrichs; Richard Hensch; Karpinski, Waclaw; Klein, Katja; Sammet, Jan Domenik; Wlochal, Michael

    2012-01-01

    The powering scheme of the CMS pixel detector will be described, and the performance of prototype DC-DC buck converters will be presented, including power efficiency, system tests with DC-DC converters and pixel modules, thermal management, reliability at low temperature, and studies of potential frequency locking betwe...

  5. Transformerless dc-Isolated Converter

    Science.gov (United States)

    Rippel, Wally E.

    1987-01-01

    Efficient voltage converter employs capacitive instead of transformer coupling to provide dc isolation. Offers buck/boost operation, minimal filtering, and low parts count, with possible application in photovoltaic power inverters, power supplies and battery charges. In photovoltaic inverter circuit with transformerless converter, Q2, Q3, Q4, and Q5 form line-commutated inverter. Switching losses and stresses nil because switching performed when current is zero.

  6. AC-DC PFC Converter Using Combination of Flyback Converter and Full-bridge DC-DC Converter

    Directory of Open Access Journals (Sweden)

    Moh. Zaenal Efendi

    2014-06-01

    Full Text Available This paper presents a combination of power factor correction converter using Flyback converter and Full-bridge dc-dc converter in series connection. Flyback converter is operated in discontinuous conduction mode so that it can serve as a power factor correction converter and meanwhile Full-bridge dc-dc converter is used for dc regulator. This converter system is designed to produce a 86 Volt of output voltage and 2 A of output current. Both simulation and experiment results show that the power factor of this converter achieves up to 0.99 and meets harmonic standard of IEC61000-3-2. Keywords: Flyback Converter, Full-bridge DC-DC Converter, Power Factor Correction.

  7. A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

    Directory of Open Access Journals (Sweden)

    Haojie Wang

    2016-07-01

    Full Text Available It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC is proposed for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control.

  8. A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

    DEFF Research Database (Denmark)

    Wang, Haojie; Han, Minxiao; Yan, Wenli

    2016-01-01

    It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC) is proposed...... for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load...... changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control....

  9. FLYWHEEL AND A DC MACHINE

    Directory of Open Access Journals (Sweden)

    IVAN ALCALÁ

    2014-01-01

    Full Text Available Este artículo describe el análisis, modelado y simulación de un vehículo eléctrico (EV enfocado al desarrollo de un banco de pruebas para reproducir la dinámica del EV. El banco está formado por un drive de motor de inducción (IM acoplado directamente a una máquina de DC y a un volante de inercia a través de una transmisión. El volante de inercia y la máquina de DC reproducen la dinámica y las fuerzas que actúan en el vehículo. Se propone una metodología para diseñar un banco de pruebas de EV para estudiar el comportamiento de vehículos eléctricos cercano a las condiciones de operación reales. El análisis de las fuerzas en el EV en conjunto con la máquina DC define las condiciones de operación del EV. El modelado y la simulación son desarrollados en MATLAB/Simulink, el banco de pruebas implementado es controlado por un DSP. Finalmente, los resultados de simulación y experimentales obtenidos validan el funcionamiento del banco de prueba.

  10. El complejo mayor de histocompatibilidad humano: sistema HLA

    Directory of Open Access Journals (Sweden)

    Luis Fernando García

    1989-02-01

    Full Text Available

    El complejo mayor de histocompatibilidad humano, o sistema HLA, está localizado en el brazo corto del cromosoma 6. Sus genes codifican tres tipos de moléculas. Los antígenos clase I (HLA-A, B, C y E están formados por una cadena pesada unida no covalentemente a la β2-microglobulina y se expresan en la superficie de la mayoría de las células nucleadas del organismo. Estos antígenos actúan como elementos de restricción en la activación de los linfocitos T CD8+. Los antígenos clase II son dímeros compuestos por cadenas α y β y su distribución tisular está limitada sólo a algunos tipos de células. Estas moléculas actúan restringiendo la presentación de antígenos a los linfocitos CD4+. Los antígenos de clase III son proteínas plasmáticas del sistema del complemento. Los diferentes loci del sistema HLA son muy polimórficos y sus productos se heredan en bloques conocidos como haplotipos. Debido a que los diferentes grupos étnicos presentan variaciones en la frecuencia de ale ios y haplotipos, el HLA ha sido muy útil en los estudios antropogenéticos. Algunos antígenos HLA están presentes en pacientes con determinadas enfermedades con una frecuencia significativamente diferente a la encontrada en la población general. Estos hallazgos han sido de gran importancia para comprender la patogénesis y los mecanismos genéticos de resistencia o susceptibilidad a dichas enfermedades. En el campo de los transplantes de órganos, la compatibilidad HLA donante-receptor correlaciona con la sobrevida del injerto. El sistema HLA también parece tener mucha importancia en los fenómenos inmunológicos que ocurren durante el

  11. Quasi-Z-Source Half-Bridge DC-DC Converter for Photovoltaic Applications

    OpenAIRE

    Vinnikov, D; Chub, A; Husev, O; Zaķis, J

    2015-01-01

    This paper presents a novel quasi-Z-source halfbridge galvanically isolated DC-DC converter intended for the photovoltaic applications. The topology could be envisioned as an alternative to the boost half-bridge DC-DC converter but the benefit of its symmetric structure reduces the threat of transformer saturation due to the dc flux. The proposed converter features the continuous input current and could be used either with one or two input voltage sources.

  12. Control of the DC-DC Converter used into Energy Generation System

    International Nuclear Information System (INIS)

    Bizon, Nicu; Oproescu, Mihai

    2006-01-01

    This paper presents an investigation of the DC-DC Converter controller used into Energy Generation System. The full bridge is used into an Energy Generation System (EGS) as second power interface between the energy source and the high DC bus. The simulation results show that the DC-DC Converter behavior can be improved using a well designed PI control surface. The used Simulink models for the EGS blocks and some design considerations are presented, too. (authors)

  13. Polifarmacia en los adultos mayores Polypharmacy in the older adults

    Directory of Open Access Journals (Sweden)

    César Martínez Querol

    2005-04-01

    Full Text Available Se realizó un estudio descriptivo de corte transversal con 118 senescentes de la población de adultos mayores del consultorio del Médico de la Familia 80.1 del Policlínico "Ana Betancourt", en el municipio Playa. A todos se les llenó una encuesta formulario que contemplaba sus datos generales, así como las enfermedades crónicas y los trastornos de los órganos de los sentidos que padecía. Se enumeraron los medicamentos que ingieren, con la dosis y periodicidad, tanto los prescritos como los autoprescritos, y se consignaron las reacciones adversas atribuidas a los fármacos consumidos. Se revisaron los controles de dispensarización y sus historias clínicas individuales.La prevalencia de polifarmacia detectada fue de 46 casos (39 %. El total de preparados prescritos fue de 303, con un promedio de 3,1 por paciente, la cifra de autoprescripciones fue 49 casos (41 % con 113 fármacos, y un promedio de preparados autorrecetados por anciano de 2,3, siendo los fármacos más indicados por los facultativos los hipotensores, los diuréticos, los psicofármacos, los analgésicos y los antidiabéticos; y entre los autorrecetados se encontraban las vitaminas, los analgésicos, los laxantes, los antihistamínicos y los psicofármacos. Las reacciones adversas se presentaron en 36 casos (37,2 %, señalándose que todas fueron ligeras y atribuidas a fármacos prescritos por los facultativos.A descriptive cross-sectional study was conducted among 118 senescents from the population of older adults of the family physician office 80.1 of "Ana Betancourt" Polyclinic, in Playa municipality. All of them answered a questionnaire to collect their general data, as well as information about the chronic diseases and disorders of the sense organs they suffered from. The drugs they were taking, both prescribed and self-prescribed, with their doses and periodicity were related, and the adverse reactions attributed to the drugs consumed were also exposed. The

  14. ZVS Operating Region of Multiresonant DC/DC Boost Conveter

    Directory of Open Access Journals (Sweden)

    Elzbieta Szychta

    2007-01-01

    Full Text Available Electromagnetic phenomena that occur during stable operation in resonant circuits of multiresonant ZVS boost converter are described, which can be applied in many fields of the needs of DC voltage electricity. The operating region of the converter is defined which assures the circuit’s operation in which semiconductor elements are switched at zero voltage (ZVS. Conditions delimiting the ZVS operating region are provided. Analysis of the circuit’s operation is based on results of simulation testing by means of Simplorer software.

  15. A Feedback Passivation Design for DC Microgrid and Its DC/DC Converters

    Directory of Open Access Journals (Sweden)

    Feifan Ji

    2016-12-01

    Full Text Available There are difficulties in analyzing the stability of microgrids since they are located on various network structures. However, considering that the network often consists of passive elements, the passivity theory is applied in this paper to solve the above-mentioned problem. It has been formerly shown that when the network is weakly strictly positive real (WSPR, the DC microgrid is stable if all interfaces between the microgrid and converters are made to be passive, which is called interface passivity. Then, the feedback passivation method is proposed for the controller design of various DC–DC converters to achieve the interface passivity. The interface passivity is different from the passivity of closed-loop systems on which the passivity based control (PBC concentrates. The feedback passivation design is detailed for typical buck converters and boost converters in terms of conditions that the controller parameters should satisfy. The theoretical results are verified by a hardware-in-loop real-time labotray (RTLab simulation of a DC microgrid with four generators.

  16. The influence of internal current loop on transient response performance of I-V droop controlled paralleled DC-DC converters

    DEFF Research Database (Denmark)

    Wang, Haojie; Han, Minxiao; Guerrero, Josep M.

    2017-01-01

    The external droop control loop of I-V droop control is designed as a voltage loop with embedded virtual impedance, so the internal current loop plays a major role in the system bandwidth. Thus, in this paper, the influence of internal current loop on transient response performance of I-V droop...... controlled paralleled dc-dc converters is analyzed, which is guided and significant for its industry application. The model which is used for dynamic analysis is built, and the root locus method is used based on the model to analyze the dynamic response of the system by shifting different control parameters...

  17. Uso tradicional de plantas medicinales en mercados de Bogot?, D.C

    OpenAIRE

    Giraldo Quintero, Sara Emilia; Bernal Lizaraz?, Mar?a Consuelo; Morales Robayo, Adriana; Pardo Lobo, Alesdy Zuled; Gamba Molano, Leopoldo

    2015-01-01

    Objetivo.Describir el uso tradicional de 26 plantas, identificando la droga vegetal, su preparaci?n y administraci?n, los fines medicinales para los que se recomiendan y posibles pr?cticas de uso inadecuado. Materiales y m?todos. Se aplicaron 16 entrevistas semiestructuradas a vendedores de plantas medicinales en 8 plazas de mercado de la ciudad de Bogot?, D.C. Adicionalmente se realiz? la identificaci?n taxon?mica de las plantas con mayor reporte por parte de los vendedores y su uso tradicio...

  18. Artificial neural network control of sab dc/dc converter

    International Nuclear Information System (INIS)

    Mahar, M.A.; Abro, M.R.; Larik, A.S.

    2009-01-01

    The latest development of power semiconductor devices enable the modern power electronic converters to withstand high voltage and high power applications. Power electronic converters are mostly periodic variable structure systems due to their switched operations. The main drawback of these converters is the generation of oscillations which are developed during the operation of the converters under nonlinear situations. To handle these nonlinearities, various researchers have proposed different control techniques. Power electronic designers are devoting in the further development of converter topologies and their control techniques. SAB (Single Active Bridge) DC/DC converter is a new topology recently introduced by Demetriades. This topology is used in high voltage and high power applications. Because of its smart features, SAB converter has recently drawn attention of many researchers. However, during the operation of SAB converter severe oscillations are generated. In this research work, a novel NNC (Neural Network Controller) model is developed for SAB converter to minimize oscillations generated during its operation. NNC is believed to be an advanced nonlinear and robust controller which has the ability to map the nonlinear behaviour in a negligible response time. The performance of SAB converter with NNC is tested under dynamic region by considering the reference voltage variation and duty ratio variation. The SAB converter is implemented and simulated in MATLAB/Simulink. The simulated results are presented. (author)

  19. Experiments with a dc motor

    International Nuclear Information System (INIS)

    Kraftmakher, Yaakov

    2010-01-01

    Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the mechanical and electrical parameters of the motor is clearly seen. The measurements are carried out with the ScienceWorkshop data-acquisition system and the DataStudio software from PASCO scientific. The experiments are well related to university courses of electricity and magnetism and can be used in undergraduate laboratories or for lecture demonstrations.

  20. Alexitimia, resiliencia y creencias paranormales en personas mayores en un centro institucionalizado

    Directory of Open Access Journals (Sweden)

    Inmaculada Méndez

    2015-08-01

    Full Text Available La alexitimia hace referencia a la dificultad para comprender e identificar los propios sentimientos y los de los demás. El proceso de adaptación a un centro residencial es una de las situaciones estresantes a las que puede enfrentarse la persona mayor. Para poder sobreponerse ante dichas situaciones es fundamental la capacidad de resiliencia e incluso existen personas que buscan apoyo en la religiosidad o en las creencias en lo paranormal. En este trabajo se estudió la relación entre aleximitia, resiliencia y creencias paranormales en un grupo de 35 personas mayores (21 mujeres con edades entre 66 y 95 años de un centro institucionalizado. Se administraron la escala TAS-20 para la evaluación de la alexitimia, la Escala de Resiliencia CD-RISC y la Escala Mejorada de Creencias Paranormales. Entre los principales resultados cabe destacar que los sujetos con mayores Dificultades para identificar sentimientos son los que presentaban un menor Control personal; los sujetos con mayores Dificultades para identificar sentimientos son los que menor creencia poseían de las Formas de vida extraordinaria y los sujetos con mayor capacidad de Control Personal son los que mayor creencia tenían de las Formas de vida extraordinaria. Se discuten las aplicaciones que los profesionales pueden poner en marcha en centros institucionalizados de personas mayores.

  1. Political Public Relations Campaign for Election of Mayor and Deputy Mayor of Solok Period 2016-2020, Creative Design Coordinator Division

    OpenAIRE

    Sanjaya, Lovegi David; M.Si, Agus Naryoso; M.Si, Much Yulianto; Gono, Joyo M S; Ayun, Primada Qurrota

    2016-01-01

    Public relations, as one of the strategies are quite effective for building the image, as well as long-term relationship with the community or public. This strategy is often combined with a political strategy to win a pair of political party candidates, which is the background of the writing of this scientific work ; the intention to won Irzal Ilyas and Alfauzi Bote as pair of political candidates to become mayor and deputy mayor of Solok period 2016-2021. There need to be applied various eff...

  2. Using PBL to Improve Educational Outcomes and Student Satisfaction in the Teaching of DC/DC and DC/AC Converters

    Science.gov (United States)

    Martinez-Rodrigo, Fernando; Herrero-De Lucas, Luis Carlos; de Pablo, Santiago; Rey-Boue, Alexis B.

    2017-01-01

    This paper examines the question of how to use project-based learning to increase student performance and satisfaction in a power electronics course addressing the topics of dc/dc and dc/ac converters, the assembly of a dc/dc converter, and the use of a commercial speed drive. A detailed presentation of the methodology is shown, and the results…

  3. Análisis del bienestar de los adultos mayores en México

    OpenAIRE

    García Benítez, Julio César

    2008-01-01

    Esta tesis analiza el bienestar de los adultos mayores en México a partir de la teoría de los funcionamientos y capacidades de Amartya Sen. La investigación tiene dos objetivos principales: el primero es medir el bienestar del adulto mayor con una visión más amplia, en el sentido de incluir tanto indicadores objetivos como subjetivos; y el segundo objetivo es demostrar que este bienestar depende tanto de los recursos, como de los factores de conversión con los que cuenta el adulto mayor, los ...

  4. Estereotipos sociales sobre la vejez en estudiantes mayores: un estudio de caso

    OpenAIRE

    Sanhueza, Javiera

    2014-01-01

    Frente al acelerado envejecimiento poblacional, se plantea el desafío de promocionar los derechos de ciudadanía de los mayores, especialmente aquellos relacionados con la participación social a través de la educación permanente. La investigación describe las imágenes sociales que las personas mayores asistentes al Aula de Mayores “Ciudad de Granada” manifiestan sobre la vejez, comparándolas según variables sociodemográficas. Se aplica el “Cuestionario de Evaluación de Estereotipos Negativos s...

  5. PACIENTE ADULTO MAYOR Y CIRUGÍA NO CARDÍACA: ¿QUÉ DEBEMOS SABER?

    OpenAIRE

    Nazar J,Claudio; Zamora H,Maximiliano; Fuentes H,Ricardo; Lema F,Guillermo

    2015-01-01

    Los procedimientos quirúrgicos en pacientes adultos mayores son cada vez más frecuentes. Se caracterizan por tener mayor morbimortalidad que los realizados en pacientes más jóvenes, por lo que es esencial una apropiada evaluación preoperatoria, una acuciosa monitorización intraoperatoria y un adecuado manejo del período postoperatorio. La edad conlleva una serie de cambios fisiológicos y una mayor incidencia de enfermedades crónicas, que en conjunto determinan una disminución de las reservas ...

  6. Funcionalidad y grado de dependencia en los adultos mayores institucionalizados en centros de bienestar

    Directory of Open Access Journals (Sweden)

    Elveny Laguado Jaimes

    Full Text Available RESUMEN Introducción: La funcionalidad en el adulto mayor constituye un eje principal para los programas orientados a fortalecer el envejecimiento activo; ante el incremento de este grupo poblacional, las enfermedades como factor que limita la capacidad física, mental y social requieren acciones de control que disminuyan la dependencia que contribuye a un deterioro mayor. Objetivo: Determinar la funcionalidad y grado de dependencia en el adulto mayor institucionalizado como información básica para el diseño de un programa de intervención específica. Metodología: estudio descriptivo retrospectivo con una muestra de 60 adultos mayores institucionalizados y seleccionados por muestreo no probabilístico. Resultados: predomina el rango de edad de 75-84 años, un 26,66% de 60 adultos mayores y el género masculino con mayor frecuencia (53,33%. Por lo que respecta a la escolaridad, el 53,3% estudiaron primaria. Contacto familiar con la familia, el 70%; tiempo de institucionalización de los adultos mayores, el mayor tiempo (55% de 1 a 5 años. Predominan los problemas cardiovasculares en el 34% de los adultos mayores. Valoración funcional: predomina el género masculino con dependencia leve (26,66% y como independiente un 25% del género femenino. La valoración del grado de autonomía en el género masculino evidencia un grado de autonomía 1, con un 30% con respecto al género femenino, que tiene un grado de autonomía 3, con el 16,66%, sin significación estadística. Conclusiones: Se observa el predominio del género masculino en los adultos mayores institucionalizados y con dependencia leve, y al contrario en las mujeres, donde la frecuencia de independencia es mayor. En la autonomía predomina un grado mayor en los hombres que en las mujeres.

  7. La sobrecarga de los cuidadores informales de personas mayores dependientes en Medina del Campo

    OpenAIRE

    Archiles Diez, Eva

    2016-01-01

    Los cuidadores informales de personas mayores dependientes constituyen un capital social de vital importancia. El hecho de cuidar a un familiar mayor dependiente, es un fenómeno cada vez más extendido que se está convirtiendo en una experiencia común en la vida familiar de muchas personas, por ello estos cuidadores suponen un capital social de enorme importancia. Este capital social, permite que las personas mayores dependientes que permanecen en el domicilio, puedan disfrutar de un nivel de ...

  8. Hierarchical Velocity Control Based on Differential Flatness for a DC/DC Buck Converter-DC Motor System

    Directory of Open Access Journals (Sweden)

    R. Silva-Ortigoza

    2014-01-01

    Full Text Available This paper presents a hierarchical controller that carries out the angular velocity trajectory tracking task for a DC motor driven by a DC/DC Buck converter. The high level control is related to the DC motor and the low level control is dedicated to the DC/DC Buck converter; both controls are designed via differential flatness. The high level control provides a desired voltage profile for the DC motor to achieve the tracking of a desired angular velocity trajectory. Then, a low level control is designed to ensure that the output voltage of the DC/DC Buck converter tracks the voltage profile imposed by the high level control. In order to experimentally verify the hierarchical controller performance, a DS1104 electronic board from dSPACE and Matlab-Simulink are used. The switched implementation of the hierarchical average controller is accomplished by means of pulse width modulation. Experimental results of the hierarchical controller for the velocity trajectory tracking task show good performance and robustness against the uncertainties associated with different system parameters.

  9. The Topologies Research of a Soft Switching Bidirectional DC/DC Converter

    DEFF Research Database (Denmark)

    Zhang, Qi; Zhang, Yongping; Sun, Xiangdong

    2017-01-01

    A soft-switching solution implemented to the traditional bidirectional DC/DC converter is developed. The soft-switching cell, which composed of three auxiliary switches, one resonant capacitor and one resonant inductor, is equipped in the traditional bidirectional DC/DC converter to realize circuit...... circle. And the proposed topology of bidirectional soft-switching dc-dc converter(TASBC) performs ideal soft switching at boost operations. The characteristics of the proposed converter has been verified by MATLAB simulations and experimental results....

  10. Elimination of output voltage oscillations in DC-DC converter using PWM with PI controller

    Directory of Open Access Journals (Sweden)

    Sreenivasappa Veeranna Bhupasandra

    2010-01-01

    Full Text Available In this paper the SIMULINK model of a PWM controlled DC-DC converter is modeled using switching function concept to control the speed of the DC motor. The presence of the voltage oscillation cycles due to higher switching frequency in the DC-DC converter is identified. The effect of these oscillations on the output voltage of the converter, Armature current, Developed torque and Speed of the DC motor is analyzed. In order to minimize the oscillation cycles the PI controller is proposed in the PWM controller.

  11. Chaos analysis and chaotic EMI suppression of DC-DC converters

    CERN Document Server

    Zhang, Bo

    2014-01-01

    Introduces chaos theory, its analytical methods and the means to apply chaos to the switching power supply design DC-DC converters are typical switching systems which have plenty of nonlinear behaviors, such as bifurcation and chaos. The nonlinear behaviors of DC-DC converters have been studied heavily over the past 20 years, yet researchers are still unsure of the practical application of bifurcations and chaos in switching converters. The electromagnetic interference (EMI), which resulted from the high rates of changes of voltage and current, has become a major design criterion in DC-DC co

  12. Alcaldes mayores y subdelegados frente a la siembra clandestina de tabaco: Papantla, 1765-1806 Alcaldes Mayores and Subdelegados coping with Tobacco Clandestine Sowing: Papantla, 1765-1806

    Directory of Open Access Journals (Sweden)

    Georgina Moreno Coello

    2012-12-01

    Full Text Available Este trabajo tiene como objeto explorar las estrategias que permitieron la persistencia de la siembra clandestina de tabaco en Nueva España, en particular en la región de Papantla. Analizar las relaciones entre los alcaldes mayores, subdelegados y empleados del monopolio del tabaco, enfatizando la protección informal de la que gozó el cultivo ilegal de parte de las autoridades provinciales y examinar cuál pudo ser el destino del ahorro, así como de las ganancias obtenidas del tabaco ilegal, particularmente en el financiamiento de actividades comerciales y crediticias que llevaban a cabo alcaldes mayores y subdelegados, especialmente en el repartimiento de mercancías.This paper explores the strategies that allowed for a persistent clandestine tobacco sowing in New Spain, mainly in the region of Papantla. It analyzes the relationship between alcaldes mayores, subdelegados and employees of the tobacco monopoly, emphasizing the informal protection given to illegal sowings by provincial authorities. It also examines the potential allocation of savings and profits from illegal tobacco, mainly in the financing of commercial activities undertaken by alcaldes mayores and subdelegados, particularly for the repartimiento.

  13. Simultaneous distribution of AC and DC power

    Science.gov (United States)

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  14. Drilling history core hole DC-8

    International Nuclear Information System (INIS)

    1978-10-01

    Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored

  15. Drilling history core hole DC-8

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored.

  16. Hubungan Kadar Feritin Serum dengan Gangguan Fungsi Paru Pasien Thalassemia Mayor Anak

    Directory of Open Access Journals (Sweden)

    Marte Robiul Sani

    2016-11-01

    Kesimpulan. Terdapat hubungan bermakna kadar feritin serum dengan gangguan fungsi paru pasien thalassemia mayor anak dan kadar feritin 4.839 μg/L merupakan batasan kadar feritin yang berhubungan dengan gangguan fungsi paru.

  17. Apendicitis aguda en el paciente senil: Factores asociados a una mayor morbimortalidad post operatoria

    Directory of Open Access Journals (Sweden)

    Víctor Eduardo Chian Chang

    1996-04-01

    Full Text Available Objetivo: Definir los factores asociados a una mayor morbilidad y mortalidad en pacientes seniles con apendicitis aguda. Material y métodos: Se realizó un estudio retrospectivo con 100 pacientes intervenidos en el Hospital Nacional Arzobispo Loayza, durante el período comprendido entre 1984 a 1994. Resultados: Se asociaron a una mayor frecuencia de complicaciones postoperatorias: edad mayor o igual a 70 años, tiempo de enfermedad mayor de 48 horas, presencia de apendicitis perforada con peritonitis localizada o generalizada (p<0.05. Además la presencia de apendicitis perforada se asoció significativamente a la presencia de absceso residual y/o fístula estercorácea (p=0.027 y la presencia de AA gangrenosa o perforada a mayor frecuencia de infección de herida operatoria (p<0.05. El antecedente de patología cardiovascular previa se asoció a mayor frecuencia de complicaciones cardiovasculares (p<0.05. Se asociaron a mayor mortalidad en AA, pacientes con intervención quirúrgica adicional a la apendicetomía (p=0.016 y presencia de AA perforada (p=0.027. Conclusiones: Los estadios avanzados de AA, así como la presencia de problema cardiovascular al momento del diagnóstico se asociaron con una mayor frecuencia de complicaciones post-operatorias. La presencia de peritonitis se asocia con la mortalidad. (Rev Med Hered 1996; 7: 62-67.

  18. De la brecha digital a la brecha psico-digital: Mayores y redes sociales

    Directory of Open Access Journals (Sweden)

    Begoña Peral Peral

    2015-07-01

    Full Text Available En el presente estudio analizamos la evolución del concepto de la brecha digital para los mayores desde la perspectiva del envejecimiento activo y en el contexto de la utilización de las redes sociales como instrumento de comunicación. Consideramos que las variables socio-demográficas no tienen suficiente poder para explicar la utilización o no de las tecnologías de la comunicación (TIC por los mayores. Las variables de corte psicológico, como la edad cognitiva, la ansiedad tecnológica o el nivel de audacia complementan a las anteriores, e incluso, pueden ser más explicativas del comportamiento del mayor con relación a la utilización de redes sociales. Los resultados provenientes de una muestra de mayores, alumnos del Aula de Experiencia de una universidad, nos permiten confirmar que nuestras dudas acerca del estereotipo de los mayores respecto a la brecha digital son acertadas y que las variables psicológicas sirven, en mayor grado, para mostrar las diferencias significativas existentes entre usuarios y no usuarios de redes sociales en cuanto a la determinación del perfil de los mismos. El usuario mayor de redes sociales se siente más joven, experimenta un menor nivel de ansiedad tecnológica y es más audaz. En general, las características psicológicas ofrecen, por tanto, mayor poder discriminante que las socio-demográficas, por ello proponemos el concepto de brecha psico-digital.

  19. Wide Temperature Range DC-DC Boost Converters for Command/Control/Drive Electronics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We shall develop wide temperature range DC-DC boost converters that can be fabricated using commercial CMOS foundries. The boost converters will increase the low...

  20. Modular Power System Configured with Standard Product Hybrid DC-DC Converters, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — VPT proposes an innovative concept whereby complex NASA space power electronic systems can be configured using a small number of qualified hybrid DC-DC converter and...

  1. Development of a DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

    CERN Document Server

    Feld, Lutz Werner; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Preuten, Marius; Max Rauch; Rittich, David Michael; Sammet, Jan Domenik; Wlochal, Michael

    2014-01-01

    A novel powering scheme based on the DC-DC conversion technique will be exploited to power the CMS Phase-1 pixel detector. DC-DC buck converters for the CMS pixel project have been developed, based on the AMIS5 ASIC designed by CERN. The powering system of the Phase-1 pixel detector is described and the performance of the converter prototypes is detailed, including power efficiency, stability of the output voltage, shielding, and thermal management. Results from a test of the magnetic field tolerance of the DC-DC converters are reported. System tests with pixel modules using many components of the future pixel barrel system are summarized. Finally first impressions from a pre-series of 200 DC-DC converters are presented.

  2. DIAGNOSTIC/PROGNOSTIC EXPERIMENTS FOR CAPACITOR DEGRADATION AND HEALTH MONITORING IN DC-DC CONVERTERS

    Data.gov (United States)

    National Aeronautics and Space Administration — Studying and analyzing the ageing mechanisms of electronic components avionics in systems such as the GPS and INAV are of critical importance. In DC-DC power...

  3. Digitally intensive DC-DC converter for extreme space environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Micro –Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

  4. Digitally intensive DC-DC converter for extreme space environments, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Micro-Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

  5. 75 FR 61352 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-30, DC-10-30F, DC-10-30F (KC...

    Science.gov (United States)

    2010-10-05

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-30, DC-10-30F, DC-10-30F (KC-10A and KDC-10...-13 McDonnell Douglas Corporation: Amendment 39-16448; Docket No. FAA-2010-0553; Directorate.... Applicability (c) This AD applies to McDonnell Douglas Corporation Model DC- 10-30, DC-10-30F, DC-10-30F (KC-10A...

  6. 75 FR 27401 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-30, DC-9-40, and DC-9-50...

    Science.gov (United States)

    2010-05-17

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 9-30, DC-9-40, and DC-9-50 Series Airplanes... airworthiness directive (AD) for certain Model DC-9-30, DC-9-40, and DC-9-50 series airplanes. This AD requires... this AD to detect and correct the potential for an arc/spark condition to occur within the fuel boost...

  7. Estudio comparativo de alexitimia en personas institucionalizadas versus aula de mayores

    Directory of Open Access Journals (Sweden)

    Julia García-Sevilla

    2016-04-01

    Full Text Available La experiencia y regulación de las emociones son aspectos que están adquiriendo mayor importancia a la hora de entender y fomentar el bienestar y la calidad de vida de las personas mayores. El objetivo del presente estudio ha sido llevar a cabo un estudio comparativo de la alexitimia en usuarios pertenecientes a un centro institucionalizado de personas mayores y alumnos matriculados en el aula de mayores. Los participantes del estudio fueron 43 personas institucionalizadas y 48 personas pertenecientes al aula de mayores con una media de edad de 69.30 años y una desviación típica de 66.50. El instrumento utilizado fue la versión adaptada del TAS-20. Los resultados mostraron que las personas institucionalizadas puntuaban más alto en la dificultad para identificar sentimientos, dificultad para describir sentimientos así como en el patrón de pensamiento orientado a lo externo. El sexo fue indiferente en la dificultad para identificar sentimientos, en la dificultad para describir sentimientos así como en el patrón orientado a lo externo. En cuanto a la edad, se encontró una relación con la dificultad para identificar sentimientos y el patrón de pensamiento orientado a lo externo. El estudio permite concluir que la alexitimia se ve influida por el hecho de que la persona mayor se encuentre en un centro institucionalizado.

  8. Nuevos mayores, viejas brechas: TIC, desigualdad y bienestar en la tercera edad en Italia

    Directory of Open Access Journals (Sweden)

    Piermarco Aroldi

    2015-07-01

    Full Text Available Italia parece tener un retraso de unos diez años en comparación con otros países más digitalizados, tanto en el uso de las TIC por las personas mayores como en el estudio de la relación entre las TIC y los mayores de 65 años. Por ello, se hace urgente examinar los factores que influyen en la adopción de las tecnologías por los mayores y la capacidad real de estas para proporcionar recursos culturales e interactivos, útiles para mejorar el envejecimiento activo y mejorar su calidad de vida en salud y vida social. Este trabajo describe los principales resultados de un estudio que involucró a 900 italianos de 65 a 74 años, en el marco de un proyecto nacional de investigación sobre el envejecimiento activo. El estudio indaga en las características sociodemográficas de los mayores italianos usuarios de Internet y en los factores que influyen en el uso de las TIC. Los resultados evidencian que existe una fuerte brecha digital entre los mayores, influenciada por el contexto económico y cultural. En cuanto al envejecimiento activo, se demuestra que los mayores altamente digitales presentan una mejor vida saludable en su envejecimiento, sin poderse concluir que el uso de las TIC garantice la inclusión y participación.

  9. La educación de los adultos mayores en TICs

    Directory of Open Access Journals (Sweden)

    Boarini, Mauricio Nazareno

    2006-01-01

    Full Text Available El siguiente trabajo pretende mostrar una propuesta de educación destinada a la capacitación de Adultos Mayores en TICs, teniendo en cuenta el contexto sociocultural actual que originan estas prácticas, su adecuación a los destinatarios y el reconocimiento que las mismas tienen por parte de los Adultos Mayores, quienes enfrentan el desafío de llevar adelante nuevos aprendizajes para sentirse integrados al grupo social con el que conviven. Atendiendo a este propósito, el trabajo se divide en tres partes; en primer lugar se incluyen diferentes proyecciones poblacionales que muestran el crecimiento de la población de Adultos Mayores a nivel mundial, y se caracteriza a la sociedad, donde la integración de las Tecnologías de la Información y la Comunicación cambia las formas de vida. En segundo lugar, se caracteriza al Adulto Mayor como sujeto destinatario de los diferentes cambios que se deben proponer desde el sistema educativo. Por último se describe la propuesta de educación de Adultos Mayores en TICs del Programa Educativo de Adultos Mayores de la Universidad Nacional de Río Cuarto y la valoración de la misma por parte de los alumnos y sociedad en general.

  10. Novel composite resonance DC-DC converter with voltage doubler rectifier

    OpenAIRE

    Kato, Hisatsugu; Matsuo, Hirohumi; Eguchi, Masaki; Sakamoto, Yukitaka; Nakaishi, Masaki

    2009-01-01

    This paper deals with a novel composite resonance DC-DC converter with the voltage doubler rectifier, which is developed to be applied to the power conditioner of the photovoltaic generation system. The proposed DC-DC converter has the current and voltage resonance functions. Therefore, the output voltage regulation can be achieved for the large variations of the input voltage and load. Also, this converter has the high power efficiency. The maximum power efficiency 96.1% can be realized.

  11. Regulation of DC development and DC-mediated T-cell immunity via CISH

    OpenAIRE

    Miah, Mohammad Alam; Bae, Yong-Soo

    2013-01-01

    Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.

  12. Regulation of DC development and DC-mediated T-cell immunity via CISH.

    Science.gov (United States)

    Miah, Mohammad Alam; Bae, Yong-Soo

    2013-03-01

    Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.

  13. Design and Analysis of Two-Phase Boost DC-DC Converter

    OpenAIRE

    Taufik Taufik; Tadeus Gunawan; Dale Dolan; Makbul Anwari

    2010-01-01

    Multiphasing of dc-dc converters has been known to give technical and economical benefits to low voltage high power buck regulator modules. A major advantage of multiphasing dc-dc converters is the improvement of input and output performances in the buck converter. From this aspect, a potential use would be in renewable energy where power quality plays an important factor. This paper presents the design of a 2-phase 200W boost converter for battery charging application. Analysis of results fr...

  14. A Fixed-Frequency Bidirectional Resonant DC-DC Converter Suitable for Wide Voltage Gain Range

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Blaabjerg, Frede

    2017-01-01

    This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant DC-DC converters, and meanwhile achieves high efficiency...... and characteristics of the proposed converter are analyzed. Finally, a 1-kW converter prototype is built and the experimental results verify the theoretical analyses....

  15. Development of a green mode DC/DC converter available to portable nuclear instrument

    International Nuclear Information System (INIS)

    Gao Feiyan; Wu Longxiong; Tan Wei; Tang Yaogeng

    2010-01-01

    A green mode DC/DC converter was developed which suitable to the portable nuclear instrument which is powered by battery and is sometime at stand-by mode. Some updated control approaches such as pseudo-resonant type power supply control and synchronous rectification were adopted to makethe DC/DC converter operate with low power consumption and high efficiency. The test results the battery can be prolonged with this converter. (authors)

  16. Superconducting dc fault current limiter

    International Nuclear Information System (INIS)

    Cointe, Y.

    2007-12-01

    Within the framework of the electric power market liberalization, DC networks have many interests compared to alternative ones, but their protections need to use new systems. Superconducting fault current limiters enable by an overstepping of the critical current to limit the fault current to a preset value, lower than the theoretical short-circuit current. For these applications, coated conductors offer excellent opportunities. We worked on the implementation of these materials and built a test bench. We carried out limiting experiments to estimate the quench homogeneity at various short-circuit parameters. An important point is the temperature measurement by deposited sensors on the ribbon, results are in good correlation with the theoretical models. Improved quench behaviours for temperatures close to the critical temperature have been confirmed. Our results enable to better understand the limitation mechanisms of coated conductors. (author)

  17. The possibility of detecting DC

    International Nuclear Information System (INIS)

    Witte, N.S.; Brown, R.D.

    1977-01-01

    IRC + 10216, a bright infrared late type carbon star, is observed to have millimetre range line emission of the species 12 CO, 13 CO, CS, C 2 H, HC 3 N, CN, HCN, SiS and SiO in an extended envelope around the central infrared sources. A model explaining the line emission in terms of infrared pumping between the two lowest vibrational levels, first proposed for IRC + 10216, was used to calculate antenna temperatures for various rotational transitions of HC 3 N; since there is a prima facie agreement between the calculated and observed values for HC 3 N we have attempted the same calculation for DC 3 N. (J.R.)

  18. Superconducting energy stabilizer with charging and discharging DC-DC converters

    International Nuclear Information System (INIS)

    Kim, S.H.; Kostecki, E.L.; DeWinkel, C.C.

    1992-01-01

    This patent describes a superconducting energy stabilizer having multiple load connections and employing DC-DC conversion for storing energy in a superconducting inductive energy storage device having a first end and a second end, and for releasing the stored energy from the superconducting inductive energy storage device to a load or loads or to a utility or an industrial electrical distribution system, the superconducting energy stabilizer having multiple load connections and employing DC-DC conversion. It comprises: energy storage cell means for supplying energy to the load, discharging DC-DC converter means for releasing energy from the superconducting inductive energy storage device to the energy storage cell means, the discharging DC-DC converter means having input terminals, output terminals, and a discharging control line means for carrying signals controlling the operation of the discharging DC-DC converter means, one of the input terminals of the discharging DC-DC converter means coupled to the first end of the superconducting energy storage device

  19. Dual wound dc brush motor gearhead

    Science.gov (United States)

    Henson, Barrie W.

    1986-01-01

    The design requirements, the design, development tests and problems, the qualification and life test and the findings of the strip examination of a dual wound DC brushed motor gearhead are described. It is the only space qualified dual wound dc brushed motor gearhead in Europe.

  20. Electronic DC transformer with high power density

    NARCIS (Netherlands)

    Pavlovský, M.

    2006-01-01

    This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

  1. DC/DC converters for integration of double-layer condensers in onboard power supply; DC/DC-Wandler zur Einbindung von Doppelschichtkondensatoren in das Fahrzeugenergiebordnetz

    Energy Technology Data Exchange (ETDEWEB)

    Polenov, Dieter

    2010-01-15

    The paper discusses DC/DC converters for integration of double layer condensers into the onboard power system. First, requirements on DC/DC converters are listed and compared on the basis of three exemplary applications. A DC/DC converter concept is developed for decoupling transient high-power loads like electric steering systems. Three different topologies are compared using a specially developed method in order to find the best solution for the given application. In order to establish adequate criteria for selecting the switching frequency and inductivities of storage throttles, the influence of the trottle power change on the switching characteristics of the MOSFETs and on certain ranges of EMP interference emissions is investigated. As methods of optimising the operation of the synchronous rectifiers, parallel connection of Schottky diodes and synchronous rectifiers as well as the variation of the shut-off dead times of synchronous rectifiers were investigated. Further, a concept for converter control was developed in consideration of the intended application and topology. Finally, selected aspects for implementation of the DC/DC converter concept are presented as well as the results of experimental investigations.

  2. Modelling of flow phenomena during DC casting

    NARCIS (Netherlands)

    Zuidema, J.

    2005-01-01

    Modelling of Flow Phenomena during DC Casting Jan Zuidema The production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an

  3. DC KIDS COUNT e-Databook Indicators

    Science.gov (United States)

    DC Action for Children, 2012

    2012-01-01

    This report presents indicators that are included in DC Action for Children's 2012 KIDS COUNT e-databook, their definitions and sources and the rationale for their selection. The indicators for DC KIDS COUNT represent a mix of traditional KIDS COUNT indicators of child well-being, such as the number of children living in poverty, and indicators of…

  4. FACTORES BIOPSICOSOCIALES ASOCIADOS A LAS ACTIVIDADES DE LA VIDA COTIDIANA DEL ADULTO MAYOR. CENTRO DE SALUD SAN JUAN DEL DISTRITO DE PAUCARPATA.AREQUIPA, 2012

    OpenAIRE

    MACEDO VALENCIA, HILDA EMILIANA

    2013-01-01

    EL ADULTO MAYOR ETAPA EVOLUTIVA DEL ADULTO MAYOR CARACTERÍSTICAS DEL ADULTO MAYOR QUE TIENEN UN ENVEJECIMIENTO SALUDABLE IMPACTO DE LAS CONDICIONES PSICOSOCIALES EN EL ADULTO MAYOR FACTORES BIO-PSICO-SOCIALES FACTORES BIOLÓGICOS FACTORES PSICOLÓGICOS FACTORES SOCIALES ACTIVIDADES DE LA VIDA COTIDIANA DEL ADULTO MAYOR

  5. The Mayor of EarthCube: Cities as an Analogue for Governing Cyberinfrastructure

    Science.gov (United States)

    Pearthree, G. M.; Allison, M. L.; Patten, K.

    2012-12-01

    Historical development of national and global infrastructure follows common paths with common imperatives. The nascent development may be led a by champion, innovator, or incubating organization. Once the infrastructure reaches a tipping point and adoption spreads rapidly, the organization and governance evolves in concert. Ultimately, no wide-spread infrastructure (from canals to highways to the electric grid to radio/television, or the Internet) operates with a single overarching governing body. The NSF EarthCube initiative is a prototype implementation of cyberinfrastructure, using the broad geoscience community as the testbed. Governance for EarthCube is emulating the pattern of other infrastructure, which we argue is a system of systems that can be described by organized complexity, emergent systems, and non-linear thermodynamics. As we consider governance cyberinfrastructure in the geosciences, we might look to cities as analogs: cities provide services such as fire, police, water, and trash collection. Cities issue permits and often oversee zoning, but much of what defines cities is outside the direct control of city government. Businesses choose whether to locate there, where to operate, and what to build. Residents make similar decisions. State and federal agencies make decisions or impose criteria that greatly affect cities, without necessarily getting agreement from them. City government must thus operate at multiple levels - providing oversight and management of city services, interaction with residents, businesses, and visitors, and dealing with actions and decisions made by independent entities over which they have little or no control. Cities have a range of organizational and management models, ranging from city managers, councils, and weak to strong mayors, some elected directly, some chosen from councils. The range and complexity of governance issues in building, operating, and sustaining cyberinfrastructure in the geosciences and beyond, rival

  6. Eritema multiforme mayor desencadenado por antimicrobianos Big multiform erythema triggered by antimicrobials

    Directory of Open Access Journals (Sweden)

    Ronaldo de Carvalho Raimundo

    2010-03-01

    Full Text Available El eritema multiforme, aparece como una enfermedad sistémica con la participación de la piel y las membranas mucosas en relación con varios factores como las infecciones bacterianas o virales, y en particular la administración de drogas, analgésicos y antibióticos en general. Se presenta un paciente masculino de 29 años de edad con eritema multiforme mayor desencadenado por antimicrobianos con la aparición de lesiones vesiculares-bulloso-ulcerosas en las regiones de los labios, encías, la lengua y la mucosa genital en tratamiento de una infección del tracto urinario con norfloxacino 400 mg por una semana. Fue realizado un tratamiento de soporte con el uso de colutorios para la higienización bucal y pomada a base de corticoide para protección de las úlceras, antihistamínicos y orientación nutricional de dieta líquida hipercalórica e hiperproteica. Este síndrome está caracterizado como un proceso eruptivo buloso agudo que compromete la calidad de vida del paciente y no hay pruebas de laboratorio específicas por lo que su diagnóstico debe estar basado en la revisión minuciosa de la anamnesis y en los hallazgos clínicos.The multiform erythema appears as a systemic disease where skin and the mucous membranes have participation in relation to some factors such as bacterial or viral infections and in particular the drugs administration, analgesics and antibiotics in general. The aim of present paper was the presentation of case of big multiform erythema triggering by antimicrobials. Authors present the case of a male patient aged 29 with appearance of ulcerous bullous-vesicular lesions in lips, gums, tongue and genital mucosa under treatment with 400 mg norfloxacin due to urinary tract infection for a week. We made support treatment using mouthwashes for oral hygiene and corticoids ointment for ulcer protection, antihistaminics and nutritional guiding of a hypercaloric and hyperprotein liquid diet. This syndrome is characterized

  7. A Component-Reduced Zero-Voltage Switching Three-Level DC-DC Converter

    DEFF Research Database (Denmark)

    Qin, Zian; Pang, Ying; Wang, Huai

    2016-01-01

    The basic Zero-Voltage Switching (ZVS) three-level DC-DC converter has one clamping capacitor to realize the ZVS of the switches, and two clamping diodes to clamp the voltage of the clamping capacitor. In order to reduce the reverse recovery loss of the diode as well as its cost, this paper...... proposes to remove one of the clamping diodes in basic ZVS three-level DC-DC converter. With less components, the proposed converter can still have a stable clamping capacitor voltage, which is clamped at half of the dc link voltage. Moreover, the ZVS performance will be influenced by removing the clamping...

  8. Improved Control Strategy for T-type Isolated DC/DC Converters

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Wang, Yanbo

    2017-01-01

    T-type isolated DC/DC converters have recently attracted attention due to their numerous advantages, including few components, low cost, and symmetrical operation of transformers. This study proposes an improved control strategy for increasing the efficiency of T-type isolated DC/DC converters....... Under the proposed strategy, the primary circulating current flows through the auxiliary switches (metal–oxide–semiconductor field-effect transistors) instead of their body diodes in free-wheeling periods. Such feature can reduce conduction losses, thereby improving the efficiency of T-type isolated DC...

  9. DC Voltage Droop Control Implementation in the AC/DC Power Flow Algorithm: Combinational Approach

    DEFF Research Database (Denmark)

    Akhter, F.; Macpherson, D.E.; Harrison, G.P.

    2015-01-01

    of operational flexibility, as more than one VSC station controls the DC link voltage of the MTDC system. This model enables the study of the effects of DC droop control on the power flows of the combined AC/DC system for steady state studies after VSC station outages or transient conditions without needing...... to use its complete dynamic model. Further, the proposed approach can be extended to include multiple AC and DC grids for combined AC/DC power flow analysis. The algorithm is implemented by modifying the MATPOWER based MATACDC program and the results shows that the algorithm works efficiently....

  10. Design of PI Controlled Non Isolated Bidirectional DC to DC Converter for Electric Vehicle Application

    Science.gov (United States)

    Geetha, A.; Subramani, C.; Thamizh Thentral, T. M.; Krithika, V.; Usha, S.

    2018-04-01

    Non isolated Bidirectional DC-DC Converter (NIBDDC) is a good interface between DC source and inverter Fed induction motor drive. This paper deals with comparison between open loop and PI controlled Bidirectional DC to DC Converter Inverter System (BDDCIS). The modelling and control of BDDC is becomes an important issue. Open loop BDDCIS and closed loop PI controlled BDDCIS are designed, modelled and simulated using Matlab- simulink and their results are presented. The investigations indicate superior performance of PI controlled BDDCIS. The proposed BDDCIS has advantages like bidirectional power transfer ability, reduced hardware count and improved dynamic response.

  11. Programa Centros Diurnos del Adulto Mayor: recomendaciones para mejorar su funcionamiento

    Directory of Open Access Journals (Sweden)

    Alejandra-Ximena Araya

    Full Text Available Resumen: Introducción: Chile se ha transformado en un país que continuará envejeciendo a un ritmo acelerado. Una de las piezas claves de la Política Integral de Envejecimiento Positivo para Chile es el desarrollo de centros de día para personas mayores (CDPM dirigidos al cuidado de ancianos con dependencia leve. Objetivo: Conocer la percepción que tiene un grupo de personas mayores, sus cuidadores y profesionales de su participación en un CDPM con el propósito de diseñar recomendaciones para mejorar este nuevo tipo de servicio geriátrico instaurado en el país. Metodología: Estudio descriptivo cualitativo realizado con 30 participantes a través de cuatro grupos focales: dos en personas mayores (n = 12, uno con cuidadores (n = 8 y uno con profesionales del centro (n = 10. El análisis de contenido se realizó según Kripperdorff y se cumplieron los criterios de rigor según Guba y Lincoln. Resultados: Se identificaron dos categorías comprensivas principales: 1 percepción de beneficios para las personas mayores: mejoría de la funcionalidad, aumento del bienestar y mayor inserción social y 2 recomendaciones de mejora del CDPM: criterios de ingreso inclusivo, flexibilidad y diversidad en actividades estipuladas y mejoras en el egreso. Conclusiones: Las personas mayores, sus cuidadores y los profesionales que los atienden coinciden en señalar que la asistencia de las personas mayores a este tipo de servicio les reporta beneficios en su funcionalidad, bienestar e inserción social. Este estudio contribuye a ampliar el entendimiento de los resultados en los usuarios de los CDPM, reportando una experiencia en un contexto social particular.

  12. Drilling history core hole DC-4

    International Nuclear Information System (INIS)

    1978-12-01

    Core hole DC-4 was completed at a depth of 3998 feet in December, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Sicsson, Inc. furnished the engineering, daily supervision of the cable tool and core drilling activities, and geological core logging for DC-4. Core hole DC-4 is located on the Hanford Site about 3 miles east of the Yakima Barricade and approximately 103 feet southwest of rotary hole DC-5, which was completed to 3990 feet in February, 1978. Hanford Site coordinates reported for hole DC-4 are north 49,385.62 feet and west 85,207.63 feet, and Washington State coordinates are north 454,468.73 feet and east 2,209,990.87 feet. No elevation survey is available for hole DC-4, but it is approximately 745 feet above mean sea level based upon the survey of hole DC-5, which has a reported elevation of 745.16 feet on the top of the 3-inch flange. The purpose of core hole DC-4 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing, cross-hole seismic shear, and pressure wave velocity studies with rotary hole DC-5. Hole DC-4 was drilled through the overburden into basalt bedrock by cable tool methods (0-623 feet) and continuously cored through the final interval (623 to 3998 feet).Core recovery was 95.8 percent of the total footage cored

  13. Controlling DC-DC converters by chaos-based pulse width modulation to reduce EMI

    International Nuclear Information System (INIS)

    Li Hong; Zhang Bo; Li Zhong; Halang, Wolfgang A.; Chen Guanrong

    2009-01-01

    In this paper, periodic and chaotic behaviors of DC-DC converters under certain parametric conditions are simulated, experimentally verified, and analyzed. Motivated by the work of J.H.B. Deane and D.C. Hamill in 1996, where chaotic phenomena are useful in suppressing electromagnetic interference (EMI) by adjusting the parameters of the DC-DC converter and making it operate in chaos, a chaos-based pulse width modulation (CPWM) is proposed to distribute the harmonics of the DC-DC converters continuously and evenly over a wide frequency range, thereby reducing the EMI. The output waves and spectral properties of the EMI are simulated and analyzed as the carrier frequency or amplitude changes with regard to different chaotic maps. Simulation and experimental results are given to illustrate the effectiveness of the proposed CPWM, which provides a good example of applying chaos theory in engineering practice.

  14. A Dual-Buck–Boost AC/DC Converter for DC Nanogrid With Three Terminal Outputs

    DEFF Research Database (Denmark)

    Wu, Weimin; Wang, Houqing; Liu, Yuan

    2017-01-01

    Due to the widely used dc characterized loads and more distributed power generation sources, the dc nanogrid becomes more and more popular, and it is seen as an alternative to the ac grid. For safety considerations, the dc nanogrid should provide reliable grounding for the residential loads...... such as the low-voltage ac power system. There are three typical grounding configurations for a dc nanogrid: the united grounding, the unidirectional grounding, and the virtual isolated grounding. Each grounding configuration has its own specifications to ac/dc converters. In this paper, a dual-buck-boost ac/dc...... converter for use in the united-grounding-configuration-based dc nanogrid with three terminal outputs is proposed. The working principle of this converter is presented in detail through analyzing the equivalent circuits. Experiments are carried out to verify the theoretical analysis....

  15. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

    Science.gov (United States)

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

  16. The copal of the Chichen Itza offerings and of the Templo Mayor of Tenochtitlan; El copal de las ofrendas de Chichen Itza y del Templo Mayor de Tenochtitlan

    Energy Technology Data Exchange (ETDEWEB)

    Montufar L, A [Subdireccion de Laboratorios y Apoyo Academico INAH, Moneda No. 6, Col Centro, 06060 Mexico D.F. (Mexico); Gutierrez W, C E; Mendoza A, D [ININ, Carr. Mexico-Toluca s/n La Marquesa, 52750 Ocoyoacac, Estado de Mexico (Mexico); Torres M, A [Facultad de Ciencias, UNAM, A.P. 20-364 01000 Mexico D.F. (Mexico)

    2006-07-01

    Literature from the post conquest shows that the Mayans used copal resins in their religious celebrations and ceremonial rites, specially as a sahumerio material. Historical precedents have been fully documented, establishing its use in the calendar ceremonies performed by the Aztecs towards their agricultural practices, mainly for the corn crop; and that according to the registries of sacred figures of their gods, they were made out of copal resin. Abundant fragments of this resin were found in a number of offerings at the digging of the Templo Mayor of Tenochtitlan. These facts indicate the intensive use of the copal as a link with divinities of life, maintenance and fertility, among many other aspects of existence, as stated by the Mexicas cosmos view. In order to determine the possible origin of the different types of copal, small samples were analyzed by infrared spectroscopy, both from Chichen Itza and the pre hispanic from Templo Mayor of Tenochtitlan. Results show a great similarity between each absorption band, the one from Templo Mayor and the modern sample Bursera bipinnata and the one from Chichen Itza and the modem resin of Protium copal. This suggests that the pre hispanic copal form Chichen Itza was obtained from the Protium copal tree. (Author)

  17. Distributed DC-UPS for energy smart buildings

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Munoz, A.; Pallares-Lopez, V.; Real-Calvo, R.J.; Gil-de-Castro, A. [Universidad de Cordoba, Area de Electronica, Dpto. Arquitectura de Computadores, Electronica y Tecnologia Electronica, Escuela Politecnica Superior, Campus de Rabanales, E-14071 Cordoba (Spain); De la Rosa, Juan Jose Gonzalez [Universidad de Cadiz, Area de Electronica, Dpto. ISA, TE y Electronica, Escuela Politecnica Superior Avda, Ramon Puyol, S/N, E-11202 Algeciras-Cadiz (Spain)

    2011-01-15

    Energy efficiency (EE) improvement is one of the most important targets to be achieved on every society as a whole and in buildings in particular. Energy Smart Building aims to accelerate the uptake of EE, healthy buildings that by integrating smart technology and solutions consume radically little resources while enhancing the quality of life. This paper addresses how uninterruptible power supply (UPS), particularly when configured in distributed DC mode, can become an Energy Efficient (EE) solution in high tech buildings, especially when integrated with complimentary Power Quality (PQ) measures. The paper is based upon PQ audits conducted at different IT-intensive modern building. Some of the mayor objectives of the PQ studies were: detecting the main involved disturbances by PQ monitoring, identifying the power disturbances root causes, characterizing the electromagnetic compatibility level of equipments and installation and providing guidelines for implementing energy-efficiency solutions. It was found that the main problems for the equipment installed were harmonics and voltage sag (dip). Finally, this paper demonstrates the impacts of generalized electronic devices on the PQ of the buildings and the implications on energy uses. (author)

  18. LA VIOLENCIA HACIA LA MUJER MAYOR: REVISIÓN BIBLIOGRÁFICA

    Directory of Open Access Journals (Sweden)

    Montserrat Celdrán

    2013-01-01

    Full Text Available A pesar de que el maltrato y la negligencia hacia las personas mayores no es una temática desconocida ni a nivel científico ni de la intervención práctica, perspectivas actuales señalan que al resaltar la edad como factor explicativo de la violencia hacia este colectivo, se ha olvidado la perspectiva de género como forma de entender y actuar sobre la violencia hacia las personas mayores. Esta revisión bibliográfica se centra en esta cuestión de género a la hora de detectar e intervenir en la violencia dirigida hacia la mujer mayor. En concreto se analizarán tres ámbitos estudiados a nivel internacional: características del maltrato hacia la mujer mayor, consecuencias de dicho maltrato a nivel de salud y calidad de vida y propuestas de intervención hacia este colectivo. El artículo quiere servir de marco para iniciar estudios a nivel nacional sobre la problemática de las mujeres mayores que sufren violencia de pareja, tema todavía inédito en nuestro entorno.

  19. Estimulación de la Inteligencia Emocional en mayores: El programa PECI-PM

    Directory of Open Access Journals (Sweden)

    Mª del Carmen Pérez-Fuentes

    2014-12-01

    Full Text Available El programa de Estimulación Cognitiva e Inteligencia Emocional para personas mayores (PECI-PM, combina técnicas de estimulación cognitiva con la intervención y estimulación sobre aspectos relacionados con la inteligencia emocional. El objetivo del presente trabajo es analizar los resultados obtenidos en inteligencia emocional, tras la primera fase de implementación del PECI-PM. Para ello, se contó con una muestra de 28 usuarios del programa, que habían completado 20 sesiones y participado en las dos evaluaciones (pre-post. La Inteligencia Emocional se evaluó, antes y después de la intervención, mediante el Inventario Breve de Inteligencia Emocional para Mayores (EQ-i-M20. Tras la intervención con el PECI-PM, se observa una mejora, en la mayoría de las dimensiones de inteligencia emocional (Intrapersonal, Interpersonal, Adaptabilidad y Estado de Ánimo. En la dimensión Manejo del Estrés, no se observa un cambio en las puntuaciones obtenidas tras la intervención, lo que lleva a replantear el peso de esta dimensión en la inteligencia emocional de la población mayor. Por otro lado, destaca el papel de la dimensión Interpersonal, que correlaciona significativamente con otros factores de la inteligencia emocional (Intrapersonal y Adaptabilidad, en mayores.

  20. Desarrollo de un Taller de risaterapia con un grupo de personas mayores

    Directory of Open Access Journals (Sweden)

    Pablo Santos M.

    2018-01-01

    Full Text Available Introducción: Las personas mayores constituyen un grupo de edad que requiere especial atención. En este contexto, se hace necesario implementar actividades que fomenten el envejecimiento activo y su bienestar psicosocial. Objetivo: se investigan los beneficios de la participación en un taller de risaterapia sobre el bienestar subjetivo y psicológico de un grupo de personas mayores a partir de su experiencia. Metodología: Estudio con enfoque cualitativo mediante entrevistas semiestructuradas a 57 personas mayores no institucionalizadas, con edades comprendidas entre los 60 y 88 años, socias de tres Centros de Día para personas mayores de la Gerencia Territorial de Servicios Sociales de Salamanca (Junta de Castilla y León. El taller de risaterapia se desarrolló durante cuatro sesiones de tres horas de duración cada una, con una periodicidad semanal. Resultados: El análisis de contenido de los discursos de los participantes develan categorías vinculadas a crecimiento personal, mejora del estado de ánimo, valoración de la risa como actividad física y lúdica, incremento de la motivación y fortalecimiento de las relaciones interpersonales. Conclusiones: Los resultados muestran los efectos positivos de los talleres de risaterapia sobre el bienestar psicológico y subjetivo de las personas mayores.

  1. Factores que inciden en la soledad residencial de las personas mayores que viven solas

    Directory of Open Access Journals (Sweden)

    Julia Gallo Estrada

    2015-03-01

    Full Text Available El aumento de la esperanza de vida, los cambios sociales y los cambios en la estructura familiar hacen que cada vez sean más y durante más tiempo las personas mayores que prefieren vivir solas, incluso cuando necesitan cuidados. Este trabajo tiene como objetivo describir el problema de la soledad residencial de las personas mayores profundizando en los factores que pueden influir en esta circunstancia. Se ha realizado una estrategia de búsqueda bibliográfica a partir de los conceptos nucleares: "personas mayores de 75 años que viven solas", "persona mayor frágil", "soporte social y entorno", "nivel de instrucción" y "familia". La información recopilada de las aportaciones científicas realizadas en este campo pone de manifiesto la necesidad de considerar prioritario conocer la opinión de las personas mayores y sus familias sobre los factores que modifican la permanencia en el domicilio.

  2. Improved DC Gun Insulator Assembly

    International Nuclear Information System (INIS)

    Neubauer, M.L.; Dudas, A.; Sah, R.; Poelker, M.; Surles-Law, K.E.L.

    2010-01-01

    Many user facilities such as synchrotron radiation light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and often exhibit poor reliability. Two technical approaches to solving this problem will be investigated. Firstly, inverted ceramics offer solutions for reduced gradients between the electrodes and ground. An inverted design will be presented for 350 kV, with maximum gradients in the range of 5-10 MV/m. Secondly, novel ceramic manufacturing processes will be studied, in order to protect triple junction locations from emission, by applying a coating with a bulk resistivity. The processes for creating this coating will be optimized to provide protection as well as be used to coat a ceramic with an appropriate gradient in bulk resistivity from the vacuum side to the air side of an HV standoff ceramic cylinder. Example insulator designs are being computer modelled, and insulator samples are being manufactured and tested

  3. Investigations of dc breakdown fields

    CERN Document Server

    Ramsvik, Trond; Reginelli, Alessandra; Taborelli, Mauro

    2006-01-01

    The need for high accelerating gradients for the future 30 GHz multi-TeV e+e- Compact Linear Collider (CLIC) at CERN has triggered a comprehensive study of DC breakdown fields of metals in UHV. The study shows that molybdenum (Mo), tungsten (W), titanium (Ti) and TiVAl reach high breakdown fields, and are thus good candidates for the iris material of CLIC structures. A significant decrease in the saturated breakdown field (Esat) is observed for molybdenum and tungsten when exposed to air. Specifically, at air pressures of 10-5 mbar, the decrease in Esat is found to be 50% and 30% for molybdenum and tungsten, respectively. In addition, a 30% decrease is found when molybdenum is conditioned with a CO pressure of ~1-10-5 mbar. Surface analysis measurements and breakdown conditioning in O2 ambience imply that the origin of the decrease in Esat is closely linked to oxide formation on the cathode surface. "Ex-situ" treatments by ion bombardment of molybdenum effectively reduce the oxide layers, and improve the brea...

  4. A THREE-PHASE BOOST DC-AC CONVERTER

    African Journals Online (AJOL)

    dc-ac converter (inverter) based on the dc-dc boost converters. ... Sliding mode controllers are designed to perform a robust control for the ... Computer simulations and spectral analysis demon- ... the conventional three-phase buck inverter,.

  5. 75 FR 75872 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-30, DC-9-40, and DC-9-50...

    Science.gov (United States)

    2010-12-07

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 9-30, DC-9-40, and DC-9-50 Series Airplanes...: We are adopting a new airworthiness directive (AD) for the McDonnell Douglas Corporation airplanes... to include an airworthiness directive (AD) that would apply to certain McDonnell Douglas Model DC-9...

  6. Pulsed-DC selfsputtering of copper

    International Nuclear Information System (INIS)

    Wiatrowski, A; Posadowski, W M; Radzimski, Z J

    2008-01-01

    At standard magnetron sputtering conditions (argon pressure ∼0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (∼550W/cm 2 ). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%

  7. Pulsed-DC selfsputtering of copper

    Science.gov (United States)

    Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.

    2008-03-01

    At standard magnetron sputtering conditions (argon pressure ~0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (~550W/cm2). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%.

  8. Biosignal-guided personalized therapy

    Directory of Open Access Journals (Sweden)

    von Stülpnagel Lukas

    2017-09-01

    Full Text Available Sudden cardiac death (SCD is the leading single cause of death in the industrialized world. Current guidelines recommend a prophylactic implantation of an implantable cardioverter-defibrillator (ICD in patients with reduced left-ventricular ejection fraction (LVEF ≤ 35%. However, most deaths after myocardial infarction (MI occur in patients with normal or moderately reduced LVEF (>35%. There is a large body of evidence that cardiac autonomic dysfunction after MI is linked to increased susceptibility to malignant arrhythmias. Deceleration capacity of heart rate (DC and periodic repolarization dynamics (PRD are novel ECG-based risk markers, which capture different facets of cardiac autonomic dysfunction. Both parameters are strong and independent predictors of mortality and SCD after MI. Previous studies indicated that combined assessment of DC and PRD allows identification of a new high-risk group among post-infarction patients that is not addressed by current guidelines, thus opening new perspectives for biosignal-guided personalized therapies.

  9. La calidad de vida de los sujetos usuarios de un centro social de personas mayores

    Directory of Open Access Journals (Sweden)

    César Bugallo Carrera

    2014-09-01

    Full Text Available En esta investigación hemos intentado comprobar si la asistencia a los centros sociales de personas mayores es un medio eficaz para la mejora de la calidad de vida de las personas mayores, es decir, si los usuarios de dichos centros tienen una mejor calidad de vida que aquellos que no acuden a ellos. Para ello, hemos contado con un grupo experimental y un grupo control. A continuación ambos grupos han pasado dos pruebas: una que valora la calidad de vida y otra, el deterioro cognitivo. Una vez pasadas las pruebas y obtenidas las puntuaciones, hemos concluido que los usuarios del centro social tienen una mayor calidad de vida que los sujetos que no acuden a él.

  10. Tratamiento del adulto mayor con síndrome coronario agudo

    Directory of Open Access Journals (Sweden)

    Carolina Pemberthy-López

    2016-11-01

    Full Text Available El adulto mayor se encuentra en una etapa de la vida con cambios fisiológicos importantes que posee repercusiones directas e indirectas sobre su estado clínico, es así como el enfoque diagnóstico y terapéutico de sus patologías debe ser abordado desde una perspectiva diferente, con consideraciones especiales para este grupo poblacional. Lamentablemente, este grupo no ha sido bien representado en los diferentes estudios y por tanto, es mucho lo que desconocemos; su comportamiento y la eficacia de las distintas terapias no están bien establecidos. Teniendo de referencia el síndrome coronario agudo como principal causa de mortalidad en pacientes mayores de 65 años de edad, abordaremos esta entidad desde la evidencia que nos aportan algunos de los registros más importantes al respecto en adultos mayores.

  11. Las personas mayores y su salud: situación actual

    OpenAIRE

    P. Ramos Cordero; J.A. Pinto Fontanillo

    2015-01-01

    El envejecimiento de la población es un fenómeno que se está produciendo en todos los países desarrollados. España es el país de Europa con una mayor esperanza de vida y el segundo país a nivel mundial tras Japón. La previsión de este envejecimiento es que se mantenga una proyección constante y que afecte ponderalmente tanto al grupo de los mayores de 65 como al grupo de los mayores de 80, lo que se viene conociendo como el envejecimiento del envejecimiento o sobreenvejecimiento de la poblaci...

  12. Superconducting DC homopolar motors for ship propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Heiberger, M.; Reed, M.R.; Creedon, W.P.; O' Hea, B.J. [General Atomic (United States)

    2000-07-01

    Superconducting DC homopolar motors have undergone recent advances in technology, warranting serious consideration of their use for ship propulsion. Homopolar motor propulsion is now practical because of two key technology developments: cryogen-free superconducting refrigeration and high performance motor fiber brushes. These compact motors are ideal for podded applications, where reduced drag and fuel consumption are predicted. In addition, the simple DC motor controller is more efficient and reliable compared with AC motor controllers. Military ships also benefit from increased stealth implicit in homopolar DC excitation, which also allows the option for direct hull or pod mounting. (authors)

  13. DC-Compensated Current Transformer †

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-01

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component. PMID:26805830

  14. High power density dc/dc converter: Selection of converter topology

    Science.gov (United States)

    Divan, Deepakraj M.

    1990-01-01

    The work involved in the identification and selection of a suitable converter topology is described. Three new dc/dc converter topologies are proposed: Phase-Shifted Single Active Bridge DC/DC Converter; Single Phase Dual Active Bridges DC/DC Converter; and Three Phase Dual Active Bridges DC/DC Converter (Topology C). The salient features of these topologies are: (1) All are minimal in structure, i.e., each consists of an input and output bridge, input and output filter and a transformer, all components essential for a high power dc/dc conversion process; (2) All devices of both the bridges can operate under near zero-voltage conditions, making possible a reduction of device switching losses and hence, an increase in switching frequency; (3) All circuits operate at a constant frequency, thus simplifying the task of the magnetic and filter elements; (4) Since, the leakage inductance of the transformer is used as the main current transfer element, problems associated with the diode reverse recovery are eliminated. Also, this mode of operation allows easy paralleling of multiple modules for extending the power capacity of the system; (5) All circuits are least sensitive to parasitic impedances, infact the parasitics are efficently utilized; and (6) The soft switching transitions, result in low electromagnetic interference. A detailed analysis of each topology was carried out. Based on the analysis, the various device and component ratings for each topology operating at an optimum point, and under the given specifications, are tabulated and discussed.

  15. CISH is induced during DC development and regulates DC-mediated CTL activation.

    Science.gov (United States)

    Miah, Mohammad Alam; Yoon, Cheol-Hee; Kim, Joonoh; Jang, Jinah; Seong, Young-Rim; Bae, Yong-Soo

    2012-01-01

    The cytokine inducible SH2-domain protein (CISH) is a well-known STAT5 target gene, but its role in the immune system remains uncertain. In this study, we found that CISH is predominantly induced during dendritic cell (DC) development from mouse bone marrow (BM) cells and plays a crucial role in type 1 DC development and DC-mediated CTL activation. CISH knockdown reduced the expression of MHC class I, co-stimulatory molecules and pro-inflammatory cytokines in BMDCs. Meanwhile, the DC yield was markedly enhanced by CISH knockdown via cell-cycle activation and reduction of cell apoptosis. Down-regulation of cell proliferation at the later stage of DC development was found to be associated with CISH-mediated negative feedback regulation of STAT5 activation. In T-cell immunity, OT-1 T-cell proliferation was significantly reduced by CISH knockdown in DCs, whereas OT-2 T-cell proliferation was not affected by CISH knockdown. CTLs generated by DC vaccination were also markedly reduced by CISH knockdown, followed by significant impairment of DC-based tumor immunotherapy. Taken together, our data suggest that CISH expression at the later stage of DC development triggers the shutdown of DC progenitor cell proliferation and facilitates DC differentiation into a potent stimulator of CTLs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Study on the Control Algorithm of Two-Stage DC-DC Converter for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Changhao Piao

    2014-01-01

    Full Text Available The fast response, high efficiency, and good reliability are very important characteristics to electric vehicles (EVs dc/dc converters. Two-stage dc-dc converter is a kind of dc-dc topologies that can offer those characteristics to EVs. Presently, nonlinear control is an active area of research in the field of the control algorithm of dc-dc converters. However, very few papers research on two-stage converter for EVs. In this paper, a fixed switching frequency sliding mode (FSFSM controller and double-integral sliding mode (DISM controller for two-stage dc-dc converter are proposed. And a conventional linear control (lag is chosen as the comparison. The performances of the proposed FSFSM controller are compared with those obtained by the lag controller. In consequence, the satisfactory simulation and experiment results show that the FSFSM controller is capable of offering good large-signal operations with fast dynamical responses to the converter. At last, some other simulation results are presented to prove that the DISM controller is a promising method for the converter to eliminate the steady-state error.

  17. Studi Komparasi Fungsi Keanggotaan Fuzzy sebagai Kontroler Bidirectional DC-DC Converter pada Sistem Penyimpan Energi

    Directory of Open Access Journals (Sweden)

    Eka Prasetyono

    2015-09-01

    Full Text Available Bidirectional DC-DC converter is needed in the energy storage system. The converter topology used in this paper was a non-isolated bidirectional DC-DC buck-boost converter. This converter worked in two ways, which the charging mode stored energy into battery when load current was less than nominal main DC current (set point and discharging mode transferred energy from battery to the load when its current exceeded set point value. Both of these modes worked automatically according to the load current. The charging and discharging currents were controlled by fuzzy logic controller which was implemented on microcontroller ARM Cortex-M4F STM32F407VG. This paper compares two types of fuzzy membership function (triangular and sigmoid in controlling bidirectional DC-DC converter. The results showed that fuzzy logic controller with triangle membership function and sigmoid as control bidirectional DC-DC converter had no significant different response, both had an average error for charging and discharging process under 4% with ripple current on the main DC bus around 0.5%. The computing time of program for fuzzy logic controller with triangular membership functions had 19.01% faster than sigmoid, and fuzzy logic computation time on a microcontroller with hardware floating point was 60% faster than software floating point.

  18. Tecnología asistencial móvil, con realidad aumentada, para las personas mayores

    Directory of Open Access Journals (Sweden)

    Rafael Saracchini

    2015-07-01

    Full Text Available Las posibilidades que ofrecen las tecnologías son muchas, sin embargo, las personas mayores son a menudo incapaces de disfrutar de ellas plenamente, sintiéndose desanimadas o intimidadas por estos nuevos dispositivos. Esto les lleva a un progresivo aislamiento en una sociedad donde es esencial conocer las distintas formas de comunicación a través de Internet y las TIC. En este trabajo presentamos un estudio realizado durante el proyecto Nacodeal, cuyo objetivo es ofrecer una solución tecnológica para proporcionar autonomía y una mejor calidad de vida para las personas mayores durante sus actividades diarias mediante la integración de las TIC. Para lograr este objetivo se ha desarrollado tecnología puntera en realidad aumentada (RA, así como servicios de Internet e interfaces para dispositivos móviles especialmente diseñados para personas mayores. Estas tecnologías emplean la infraestructura presente en la mayoría de casas y centros de cuidados de mayores. Presentamos un prototipo de sistema compuesto por una tableta y un dispositivo de RA portátil, así como el análisis del impacto social en la interacción con usuarios y la valoración de la aceptación y usabilidad. Esta evaluación se llevó a cabo a través de grupos focales y pruebas piloto individuales con 48 participantes: ancianos, cuidadores y expertos. Sus comentarios concluyen que existen fuertes beneficios e intereses por parte de las personas mayores en las TIC asistenciales basadas en RA, especialmente en los aspectos relacionados con la comunicación y autonomía.

  19. Prevalencia de polifarmacia en adultos mayores residentes de asilos de Hermosillo, Sonora

    Directory of Open Access Journals (Sweden)

    Andrés Canale Segovia

    2014-12-01

    Full Text Available El término polifarmacia se refiere a la utilización de múltiples fármacos por una persona, de manera constante. Debido a que los adultos mayores constituyen el grupo etario con mayor prevalencia de enfermedades crónico-degenerativas, la polifarmacia es un fenómeno común en poblaciones geriátricas. No se conoce con precisión cuál es la prevalencia en un grupo de ancianos asilados del estado de Sonora. Se realizó un estudio transversal, para estimar la prevalencia de polifarmacia en una muestra no probabilística de adultos mayores residentes de asilos de ancianos de Hermosillo, Sonora. La prevalencia de polifarmacia (definida como consumo concomitante de 4 o más fármacos fue de 36.1%, sin diferencias significativas respecto al tipo de enfermedades crónicas padecidas, así como a la edad y sexo de los ancianos asilados. Los sujetos con polifarmacia tuvieron un exceso de riesgo, superior a 10 veces, cuando la prescripción farmacológica era realizada por más de un médico, y tuvieron 5 veces más probabilidad de presentar algún efecto adverso a medicamentos respecto a los sujetos con ausencia de polifarmacia. La polifarmacia es un fenómeno que requiere mayor atención, control e investigación futura, toda vez que los adultos mayores son el grupo poblacional con mayor tendencia de crecimiento en México.

  20. Suicidio en adultos mayores en Costa Rica durante el período 2010-2014

    OpenAIRE

    Vargas Sanabria, Maikel; Vega Chaves, Juan Carlos; Montero Solano, Gustavo; Hernández Romero, Gabriel

    2017-01-01

    Resumen:La población mayor de 65 años es un grupo vulnerable a cometer suicidio, con riesgo 1.5 veces mayor con respecto a los jóvenes. El envejecimiento y sus cambios retan al individuo, de manera que su fracaso predispone a conductas suicidas.Estas tienen mucho más probabilidad de ser letales en comparación con cualquier otro grupo etario. Hay poca investigación en relación con las características epidemiológicas asociadas a este tema. Este artículo pretende describir los principales factor...

  1. Personas mayores y nuevas tecnologias. Propuesta de intervencion con dispositivos moviles

    OpenAIRE

    Pereira García, César Gualter

    2014-01-01

    En el presente trabajo, se proponen los cauces sobre los que llevar a cabo, una intervención psicopedagógica, interrelacionando tres elementos definidos por unas características concretas a contemplar de manera particular; las personas mayores, las características de la sociedad actual, y las tecnologías de la información y comunicación. El constatado aumento de la población, observado este de manera significativa en las personas de mayor edad, exige la implementación de contin...

  2. INCREMENTO DE LA AUTOESTIMA EN LOS ADULTOS MAYORES DE UN HOGAR DE JUBILADOS

    OpenAIRE

    Teresa de Jesús Mazadiego Infante; Janeth Calderón Reyes; Claudia Solares Mejía; Maribel Zárate Moreno; Lisseth Torres Vargas; Ángel de Jesús Coto Sampayo

    2011-01-01

    El objetivo de este trabajo fue probar la efectividad de las técnicas de relajación, terapia ocupacional y dinámicas grupales para mejorar la autoestima de los adultos mayores de una casa-hogar para jubilados. Al efecto, se trabajó con una muestra de 17 adultos mayores, a quienes se asignaron diversas actividades, como ejercicios musicales, juegos de mesa, manualidades y sesiones de intercambio de experiencias y expresión de sentimientos. Los resultados obtenidos muestran un incremento consid...

  3. Estrategias orientadoras apara la elaboración de proyectos de adultos mayores

    OpenAIRE

    Ciano, Natalia

    2011-01-01

    En este trabajo se presenta el proyecto de investigación "estrategias orientadoras para la elaboración de proyectos en adultos mayores" que se propone aplicar las estrategias orientadoras diseñadas en un proyecto anterior a los efectos de analizar el impacto de las mismas en la elaboración de proyectos de adultos mayores. Articula el Modelo de Envejecimiento Activo y el Modelo Teórico Operativo en Orientación. Se parte de los principales resultados obtenidos en la investigación anterior, los ...

  4. ACTIVIDADES DE LA VIDA DIARIA EN ADULTOS MAYORES: LA EXPERIENCIA DE DOS GRUPOS FOCALES

    OpenAIRE

    Christian Oswaldo Acosta Quiroz; Ana Luisa Mónica González-Celis Rangel

    2010-01-01

    El presente estudio tuvo como objetivo obtener una muestra de ejemplos de actividades recreativas físicas y mentales, sociales, de independencia y de protección a la salud, como propuesta inicial de un inventario de actividades de la vida diaria en adultos mayores, a través del desarrollo de dos grupos focales organizados alrededor del tema de actividades cotidianas en ancianos, con ocho y quince adultos mayores, respectivamente. Los resultados reflejan una amplia variedad de actividades de l...

  5. Factores asociados al riesgo nutricional del adulto mayor no institucionalizado, Pasto, Colombia

    OpenAIRE

    Hernández Rangel, Juanita del Pilar

    2017-01-01

    Objetivo: determinar los factores sociales, demográficos, y de salud que se asocian al riesgo nutricional de los adultos mayores no institucionalizados de la ciudad de Pasto en el año 2016. Metodología: estudio de prevalencia analítico a partir del análisis secundario de los datos para la ciudad de Pasto de la encuesta “Índice de vulnerabilidad de los adultos mayores, en tres ciudades de Colombia, 2016”. Se utilizó la Iniciativa del Tamizaje Nutricional (NSI) con la escala DETERMINE para l...

  6. Prevalencia y factores de riesgo en personas adultas mayores en Costa Rica

    OpenAIRE

    Barrientos Calvo, Isabel; Madrigal Leer, Fabián; Abarca Gómez, Leandra

    2014-01-01

    El riesgo nutricional es la potencialidad de desarrollar desnutrición por déficit de alimentación, debido a diversos factores. La prevalencia del riesgo nutricional en adultos mayores utilizando la Valoración Nutricional Mínima (MNA®) en Europa y Estados Unidos es de un 15 % y 20 %. El estudio SABE-México, determinó un 31,8 %. Objetivo: Conocer la prevalencia de riesgo nutricional y sus principales factores asociados en los adultos mayores que asisten a un primer nivel de atención en Costa Ri...

  7. Factores de bienestar laboral : percepción de los trabajadores de mayor edad /

    OpenAIRE

    González Gómez de Olmedo, María Paz

    2014-01-01

    Introducción: La situación demográfica y económica Europea, con la consecuente prolongación de la vida laboral, plantea la necesidad de desarrollar estratégias que permitan, a los trabajadores mayores, conservar la capacidad de trabajo, con salud y bienestar. Objetivos de investigación: - Identificar, empíricamente, en contextos laborales específicos, los factores que, desde la percepción de los trabajadores mayores, estan relacionados con el bienestar y la intención de continuar laboralmente...

  8. El estado de salud del adulto mayor en América Latina

    OpenAIRE

    R. Todd Jewell; Máximo Rossi; Patricia Triunfo

    2006-01-01

    Haciendo uso de los datos de la Encuesta sobre Salud, Bienestar y Envejecimiento, este trabajo analiza el estado de salud de las personas mayores a 60 años en cinco países de América Latina: Argentina, Brasil, Chile, México y Uruguay. Empleando modelos probit ordenados fue posible investigar los efectos de variables socioeconómicas sobre el estado de salud auto-reportado. Los resultados indican que la autopercepción de la salud está relacionada positivamente con una buena nutrición, una mayor...

  9. Relación entre masa ósea y agilidad en personas mayores

    OpenAIRE

    A. Gómez-Cabello; G. Vicente-Rodríguez; A. González-Agüero; I. Ara; J. A. Casajús

    2010-01-01

    El objetivo de este estudio fue analizar la asociación entre masa ósea y agilidad en personas mayores. Se evaluó a 223 participantes mayores de 65 años (64 hombres y 159 mujeres) de Zaragoza (España). Se midió el área, contenido (CMO) y densidad mineral ósea (DMO) en el cuerpo completo, columna lumbar y cadera mediante absorciometría fotónica dual de rayos X (...

  10. Desarrollo en planta piloto de una bebida de lacto suero y fruta natural para adultos mayores /

    OpenAIRE

    Villarreal Arizpe, Beatriz,

    2017-01-01

    Departament responsable de la tesi: Departament de Ciència Animal i dels Aliments. México es el 18 país a nivel mundial, de los mayores productores de leche, el 55% se destina a la producción de los quesos frescos, el subproducto principal es el lacto suero. Los adultos mayores, ocupan gran porcentaje de los habitantes del país, grupo con alta prevalencia de enfermedades relacionadas con estilos de vida no saludables. La innovación de productos en base a subproductos, con adición de ingred...

  11. Estudio sobre la pertinencia del uso de las normas disponibles del Raven en adultos mayores chilenos

    OpenAIRE

    Alarcón Paz,Cristina; Díaz Valenzuela,Vanessa; Hernández Rosales,Jacqueline; Estrada Goic,Claudia

    2012-01-01

    La evaluación de la inteligencia en población adulto mayor ha aumentado su relevancia debido al incremento de la esperanza de vida. Este estudio centra su interés en la pertinencia de normas disponibles para el Test de Matrices Progresivas de Raven para dicha población. Se utilizaron normas de Colchester (1942, en Raven, Court y Raven, 2008), las más completas existentes. Participaron 102 adultos mayores voluntarios (más de 60 años). El diseño fue no experimental transversal correlacional. Lo...

  12. Competencias socio-emocionales en adultos mayores de la ciudad de Buenos Aires

    OpenAIRE

    Mikulic, Isabel M.; Caballero, Romina; Aruanno, Yanina

    2014-01-01

    Con el aumento de la población de adultos mayores, se plantean importantes retos a nivel internacional. Los estudios se focalizaron en factores demográficos, cognitivos y físicos, en cambio, los emocionales fueron escasamente investigados en esta etapa vital. El objetivo de este estudio es evaluar el patrón de competencias socioemocionales en 53 adultos mayores (M =69; DE =4.2), de ambos sexos, y comparar sus diferencias con 53 jóvenes adultos. A todos los participantes se les administró el I...

  13. Exceso de peso y discapacidad en las personas mayores de la Argentina

    OpenAIRE

    Malena Monteverde

    2015-01-01

    El objetivo del presente trabajo es analizar la relación entre el exceso de peso y la condición de discapacidad en las personas mayores de la Argentina y evaluar en qué medida podría estar operando algún factor protector que reduzca o atenúe el efecto del exceso de peso sobre la pérdida de capacidades funcionales en las personas mayores de 64 años. Para ello se utilizan los microdatos de la Encuesta Nacional de Factores de Riesgo 2009. Con el objeto de medir la asociación entre sobrepeso, obe...

  14. Factores que inciden en la soledad residencial de las personas mayores que viven solas

    OpenAIRE

    Julia Gallo Estrada; Jesús Molina Mula

    2015-01-01

    El aumento de la esperanza de vida, los cambios sociales y los cambios en la estructura familiar hacen que cada vez sean más y durante más tiempo las personas mayores que prefieren vivir solas, incluso cuando necesitan cuidados. Este trabajo tiene como objetivo describir el problema de la soledad residencial de las personas mayores profundizando en los factores que pueden influir en esta circunstancia. Se ha realizado una estrategia de búsqueda bibliográfica a partir de los conceptos nucleare...

  15. Actividad física, ejercicio físico y adulto mayor

    OpenAIRE

    Ozols R., Ma Antonieta; Corrales Araya, Ma Antonieta

    2017-01-01

    Se ha comprobado que la actividad física y el ejercicio mejoran la calidad de vida de las personas mayores. Las investigaciones han encontrado progresos en el plano físico, emocional y social. Una de las organizaciones que está promoviendo estilos de vida saludables es la Organización Mundial de la Salud, que ha enfocado su atención en todas las etapas de la vida: desde la niñez hasta la edad adulta mayor.

  16. Programa de entrenamiento en habilidades sociales con personas mayores con discapacidad auditiva y visual leve

    OpenAIRE

    García Carracedo, Laura

    2014-01-01

    A partir de la hipótesis de que la mejora en habilidades sociales va a repercutir en mejorar la calidad de vida de las personas mayores, se ha desarrollado un programa de intervención dirigido a personas mayores con discapacidad auditiva y visual leve procedentes de la residencia “Casa Beneficencia” situada en la calle camino del cementerio en Valladolid. En el presente trabajo hemos utilizado diversas técnicas para la recogida de información previa y posterior diagnóstico de las necesidad...

  17. Medicines and You: A Guide for Older Adults = Las medicinas y usted: Guia para las personas mayores.

    Science.gov (United States)

    National Coalition of Hispanic Health and Human Services Organizations.

    Most people over 65 take many prescription and nonprescription medicines. Because the body is changing and more medicines are taken, many older adults experience harmful reactions to the medicines they take. This booklet, written in both English and Spanish (on facing pages), was developed to help older adults learn more about medicines, recognize…

  18. A green roof grant program for Washington DC

    International Nuclear Information System (INIS)

    Johnson, P.A.

    2007-01-01

    The Chesapeake Bay Foundation (CBF) began its green roof demonstration project with $300,000 in funding provided by the DC Water and Sewer Authority. This paper reviewed the history of the project, its goals and early findings. The main objective was to demonstrate the technical, policy and economic feasibility of installing green roofs on commercial buildings in Washington DC and to promote green roofs as a means to manage storm water and improve water quality through the reduction of excessive runoff. The CBF has issued grants for the installation of 7 green roofs varying in size, design, location, and use. The projects included both new and existing structures designed to improve storm-water management in an urban area with significant pollution stress on the adjacent rivers. This paper provided technical, cost, and performance evaluations of each roof. A public outreach segment provided information to decision-makers to encourage more widespread replication of green roof technology throughout the metropolitan area. Much of the District of Columbia is served by a combined sewer system that becomes overloaded and discharges raw sewage into adjacent rivers during even moderately heavy rains. An average of 75 overflow events each year result in 1.5 billion gallons discharged into the Anacostia River. The installation of green roofs on buildings in the combined sewer area would retain storm water during these heavy rains and reduce the amount of overflow discharges. Apartments, as well as commercial and government buildings with mostly flat roofs are the most likely candidates for green roofs. The demonstration roofs are intended to become models, which all building owners could use as a guide for future plans for construction or re-construction to expand green roof coverage in Washington DC. It was emphasized that although such large-scale replication will take time and financial investments, it is achievable given enough political will and commercial awareness of

  19. NAMMA DC-8 DROPSONDE V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The DC-8 dropsonde system uses an integrated, highly accurate, GPS-located atmospheric profiling dropsonde, which measures and records current atmospheric conditions...

  20. dc power system for deuteron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Creek, K.O.; Liska, D.J.

    1981-01-01

    The Fusion Materials Irradiation Test (FMIT) Facility dc power system provides excitation current for all linac and High-Energy Beam Transport (HEBT) quadrupole and bending magnets, excitation for horizontal and vertical beam steering, and current-bypass shunts.

  1. Determination of input/output characteristics of full-bridge AC/DC/DC converter for arc welding

    OpenAIRE

    Stefanov, Goce; Karadzinov, Ljupco; Sarac, Vasilija; Cingoski, Vlatko; Gelev, Saso

    2016-01-01

    This paper describes the design and practical implementation of AC/DC/DC converter in mode of arc welding. An analysis of the operation of AC/DC/DC converter and its input/output characteristics are determined with computer simulations. The practical part is consisted of AC/DC/DC converter prototype for arc welding with output power of 3 kW and switching frequency of 64 kHz. The operation of AC/DC/DC converter is validated with experimental measurements.

  2. Ultra-high Efficiency DC-DC Converter using GaN Devices

    DEFF Research Database (Denmark)

    Ramachandran, Rakesh

    2016-01-01

    properties of GaN devices can be utilized in power converters to make them more compact and highly efficient. This thesis entitled “Ultra-high Efficiency DC-DC Converter using GaN devices” focuses on achieving ultra-high conversion efficiency in an isolated dc-dc converter by the optimal utilization of Ga...... for many decades. However, the rate of improvement slowed as the silicon power materials asymptotically approached its theoretical bounds. Compared to Si, wideband gap materials such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are promising semiconductors for power devices due to their superior...... in this thesis. Efficiency measurements from the hardware prototype of both the topologies are also presented in this thesis. Finally, the bidirectional operation of an optimized isolated dc-dc converter is presented. The optimized converter has achieved an ultra-high efficiency of 98.8% in both directions...

  3. Modeling, Analysis and Control of Different DC-DC Converter Topologies for Photo Voltaic Emulator

    Directory of Open Access Journals (Sweden)

    Mohammad Tauquir Iqbal

    2016-05-01

    Full Text Available This paper presents the modeling, analysis and control of different DC-DC converter topologies to emulate the photovoltaic (PV system. A PV emulator is basically a DC-DC converter having same electrical characteristics that of solar PV panel.  The emulator helps to achieve real characteristics of PV system in a better way in an environment where using actual PV systems can produce inconsistent results due to variation in weather conditions. The paper describes different types of DC-DC converters like buck, Resonant and Quasi Resonant Converter. The complete system is modelled in MATLAB® Simulink SimPowerSystem software package. The Simulation results obtained from the MATLAB® Simulink SimPowerSystem software package for different topologies under steady and dynamic conditions are analyzed and presented. An evaluation table is also presented at the end of the paper, presenting the effectiveness of each topology.

  4. Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

    Science.gov (United States)

    Lee, F. C.; Mahmoud, M. F.; Yu, Y.

    1980-01-01

    The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

  5. Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

    Science.gov (United States)

    Lee, F. C.; Mahmoud, M. F.; Yu, Y.

    1980-04-01

    The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

  6. Test Results of Selected Commercial DC/DC Converters under Cryogenic Temperatures - A Digest

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad

    2010-01-01

    DC/DC converters are widely used in space power systems in the areas of power management and distribution, signal conditioning, and motor control. Design of DC/DC converters to survive cryogenic temperatures will improve the power system performance, simplify design, and reduce development and launch costs. In this work, the performance of nine COTS modular, low-tomedium power DC/DC converters was investigated under cryogenic temperatures. The converters were evaluated in terms of their output regulation, efficiency, and input and output currents. At a given temperature, these properties were obtained at various input voltages and at different load levels. A summary on the performance of the tested converters was given. More comprehensive testing and in-depth analysis of performance under long-term exposure to extreme temperatures are deemed necessary to establish the suitability of these and other devices for use in the harsh environment of space exploration missions.

  7. Precharge strategies for isolated modular DC-DC converters under two different start-up conditions

    DEFF Research Database (Denmark)

    Zhang, Yi; Wang, Huai; Li, Binbin

    2017-01-01

    The isolated modular DC-DC converter (IMDCC) is a new topology designed to connect high-voltage direct current (HVDC) lines with different voltage levels, which ties two DC grids by using two modular multilevel converters (MMCs) via a medium-frequency transformer. Due to the large value of capaci......The isolated modular DC-DC converter (IMDCC) is a new topology designed to connect high-voltage direct current (HVDC) lines with different voltage levels, which ties two DC grids by using two modular multilevel converters (MMCs) via a medium-frequency transformer. Due to the large value...... of capacitance in the IMDCC, proper precharge strategies before the start-up are significant for the safety and reliability of the whole system. This paper presents two closed-loop precharge control strategies to fully charge the sub-module (SM) capacitors of the IMDCC, considering two different start...

  8. Guided labworks

    DEFF Research Database (Denmark)

    Jacobsen, Lærke Bang

    For the last 40 years physics education research has shown poor learning outcomes of guided labs. Still this is found to be a very used teaching method in the upper secodary schools. This study explains the teacher's choice of guided labs throught the concept of redesign as obstacle dislodgement...

  9. Kingsnorth-London dc transmission link

    Energy Technology Data Exchange (ETDEWEB)

    1966-03-11

    The hvdc transmission link between one of the 500 MW generators at Kingsnorth Power Station and two receiving stations in London will use a three-wire dc cable system rated to carry 1200 A at +- 266 kV. This 51-mile system will be the first dc link in the world to be used as an integral part of a complex interconnected ac network.

  10. Hole history, rotary hole DC-3

    International Nuclear Information System (INIS)

    1977-10-01

    Purpose of hole DC-3 was to drill into the Umtanum basalt flow using both conventional rotary and core drilling methods. The borehole is to be utilized for geophysical logging, future hydrological testing, and the future installation of a borehole laboratory for long-term pressure, seismic, and moisture migration or accumulation recording in the Umtanum basalt flow in support of the Basalt Waste Isolation Program. Hole DC-3 is located east of the 200 West barricaded area on the Hanford reservation

  11. DC-8 MTP calibration for SOLVE-2

    Science.gov (United States)

    Mahoney, M. J.

    2003-01-01

    The Jet Propulsion Laboratory (JPL) Microwave Temperature Profiler (MTP) was the only instrument making temperature measurements at and below flight level on the DC-8 during the SOLVE-2 campaign. Many years of careful comparison of MTP measurements with radiosondes near the DC-8 flight track have shown that the flight level temperature can be determined to an accuracy of 0.2K relative to radiosondes.

  12. dc illusion and its experimental verification

    Science.gov (United States)

    Liu, Min; Lei Mei, Zhong; Ma, Xiang; Cui, Tie Jun

    2012-07-01

    Based on the transformation optics method, we propose a dc illusion device, which can transform a metallic object into a magnified dielectric object using anisotropic conducting materials. Utilizing the analogy between electric conductivities and resistor networks, we design and fabricate the device using metal film resistors. The practical measurement data agree very well with simulation results. The proposed dc illusion device is easy to process and measure, and thus has potential applications in various sectors.

  13. Characterization of diode valve in medium voltage dc/dc converter for wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne

    2016-01-01

    This paper proposes a methodology for characterization of medium voltage (MV), medium frequency (MF) rectifier diode valve. The intended application is for 10MW dc/dc converters used in DC offshore wind turbines. Sensitivity to semiconductor component parameter variation, snubber component tolera...... tolerance, influence of temperature and stray capacitance are analyzed. It is concluded that the largest impact on sensitivity is given by reverse recovery charge variation and differences of temperature between adjacent devices....

  14. Computer Simulation of Phase Shifted Series Resonant DC to DC Converter

    Directory of Open Access Journals (Sweden)

    P. PARVATHY

    2016-01-01

    Full Text Available This paper deals with digital simulation of phase shifted series resonant DC to DC converter using Matlab Simulink. The Simulink models for open loop and closed loop systems are developed and they are used for simulation studies. This converter is capable of producing ripple free DC output. Switching losses and switching stresses are reduced by using soft switching. This converter has advantages like high power density and low switching losses. Theoretical predictions are well supported by the simulation results.

  15. DC-Link Compensation Method for Slim DC Link Drives Fed by Soft Grid

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Rosendahl Andersen, Henrik; Lazar, Radu

    2010-01-01

    Slim DC-link PWM (AC) drives for lowperformance applications are emerging on the market. Such drives equipped with a small DC-link capacitance exhibit instability tendencies, if installed on a soft line, giving a degraded performance. The total harmonic distortion (THD) and the partially weighted...... harmonic distortion (PWHD) of the line current are degraded, if resonance between the line impedance and the DC-link capacitance occurs. Likewise, the motor performance is affected negatively giving extra torque ripple, vibration and acoustic-noise emission. This paper proposes a novel DC-link compensation...

  16. Egr2 induced during DC development acts as an intrinsic negative regulator of DC immunogenicity.

    Science.gov (United States)

    Miah, Mohammad Alam; Byeon, Se Eun; Ahmed, Md Selim; Yoon, Cheol-Hee; Ha, Sang-Jun; Bae, Yong-Soo

    2013-09-01

    Early growth response gene 2 (Egr2), which encodes a zinc finger transcription factor, is rapidly and transiently induced in various cell types independently of de novo protein synthesis. Although a role for Egr2 is well established in T-cell development, Egr2 expression and its biological function in dendritic cells (DCs) have not yet been described. Here, we demonstrate Egr2 expression during DC development, and its role in DC-mediated immune responses. Egr2 is expressed in the later stage of DC development from BM precursor cells. Even at steady state, Egr2 is highly expressed in mouse splenic DCs. Egr2-knockdown (Egr2-KD) DCs showed increased levels of major histocompatability complex (MHC) class I and II and co-stimulatory molecules, and enhanced antigen uptake and migratory capacities. Furthermore, Egr2-KD abolished SOCS1 expression and signal transducer and activator of transcription 5 (STAT5) activation during DC development, probably resulting in the enhancement of IL-12 expression and Th1 immunogenicity of a DC vaccine. DC-mediated cytotoxic T lymphocyte (CTL) activation and antitumor immunity were significantly enhanced by Egr2-KD, and impaired by Egr2 overexpression in antigen-pulsed DC vaccines. These data suggest that Egr2 acts as an intrinsic negative regulator of DC immunogenicity and can be an attractive molecular target for DC vaccine development. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Analysis of high voltage step-up nonisolated DC-DC boost converters

    Science.gov (United States)

    Alisson Alencar Freitas, Antônio; Lessa Tofoli, Fernando; Junior, Edilson Mineiro Sá; Daher, Sergio; Antunes, Fernando Luiz Marcelo

    2016-05-01

    A high voltage step-up nonisolated DC-DC converter based on coupled inductors suitable to photovoltaic (PV) systems applications is proposed in this paper. Considering that numerous approaches exist to extend the voltage conversion ratio of DC-DC converters that do not use transformers, a detailed comparison is also presented among the proposed converter and other popular topologies such as the conventional boost converter and the quadratic boost converter. The qualitative analysis of the coupled-inductor-based topology is developed so that a design procedure can be obtained, from which an experimental prototype is implemented to validate the theoretical assumptions.

  18. High-Voltage DC-DC Converter Topology for PV Energy Utilization - Investigation and Implementation

    DEFF Research Database (Denmark)

    Sanjeevikumar, Padmanaban; Blaabjerg, Frede; Wheeler, Patrick

    2017-01-01

    This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic...... elements suppress the power transfer ratio, converter needs to maximize the PV energy utilization. This investigation study focused to include additional parasitic elements (voltage-lift technique) to a standard DC-DC buck converter and to overcome all the above drawbacks to maximize the PV power...

  19. Digital peak current mode control with adaptive slope compensation for DC-DC converters

    DEFF Research Database (Denmark)

    Andersen, Karsten Holm; Nymand, Morten

    2017-01-01

    performance and stability of current mode control. The presented method adapt to DC-DC converter operating conditions by estimating the rising and falling inductor current slopes, to apply a current slope compensation value to obtain a constant quality factor. The experimental results verifies the theoretical......This paper presents an adaptive slope compensation method for peak current mode control of digital controlled DC-DC converters, which controls the quality factor of the complex conjugated poles at half the switching frequency. Using quality factor control enables optimization of the dynamic...

  20. A Novel PPFHB Bidirectional DC-DC Converter for Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase-shift modula......This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase...

  1. The application of standardized control and interface circuits to three dc to dc power converters.

    Science.gov (United States)

    Yu, Y.; Biess, J. J.; Schoenfeld, A. D.; Lalli, V. R.

    1973-01-01

    Standardized control and interface circuits were applied to the three most commonly used dc to dc converters: the buck-boost converter, the series-switching buck regulator, and the pulse-modulated parallel inverter. The two-loop ASDTIC regulation control concept was implemented by using a common analog control signal processor and a novel digital control signal processor. This resulted in control circuit standardization and superior static and dynamic performance of the three dc-to-dc converters. Power components stress control, through active peak current limiting and recovery of switching losses, was applied to enhance reliability and converter efficiency.

  2. Laboratory manual for pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2015-01-01

    Designed to complement a range of power electronics study resources, this unique lab manual helps students to gain a deep understanding of the operation, modeling, analysis, design, and performance of pulse-width modulated (PWM) DC-DC power converters.  Exercises focus on three essential areas of power electronics: open-loop power stages; small-signal modeling, design of feedback loops and PWM DC-DC converter control schemes; and semiconductor devices such as silicon, silicon carbide and gallium nitride. Meeting the standards required by industrial employers, the lab manual combines program

  3. A Bidirectional Multi-Port DC-DC Converter Integrating Voltage Equalizer

    DEFF Research Database (Denmark)

    Chen, Jianfei; Hou, Shiying; Deng, Fujin

    2015-01-01

    A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalize...... battery modules with different voltages. Simulation results has shown the feasibility of the proposed converter.......A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalized...

  4. A Bidirectional Resonant DC-DC Converter Suitable for Wide Voltage Gain Range

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Al-Durra, Ahmed

    2018-01-01

    This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant dc-dc converters, and meanwhile achieves high efficiency...... losses. The operation principles and characteristics of the proposed converter are firstly analyzed in this paper. Then the analytical solutions for the voltage gain, soft-switching, and rms currents are derived, which facilitates the parameters design and optimization. Finally, the proposed topology...... and analysis are verified with experimental results obtained from a 1-kW converter prototype....

  5. Design of the DC-DC power stage of the capacitor charger for MAXIDISCAP power converters

    CERN Document Server

    Cravero, Jean-Marc

    2013-01-01

    This technical report presents the design of the DC-DC power stage of the capacitor charger for MAXIDISCAP power converters. The power stage is based on a half bridge series resonant converter in Discontinuous Conduction Mode (DCM). This simple and robust topology allows obtaining a current source behavior with a low switching losses power stage. The associated control stage is implemented using a commercial controller which has differenti nternal circuits that allows a high integration of the converter control system. The report presents the design and tuning criteria for the DC-DC converter, including the power stage and the control system.

  6. Alcaldes mayores y subdelegados frente a la siembra clandestina de tabaco: Papantla, 1765-1806 Alcaldes Mayores and Subdelegados coping with Tobacco Clandestine Sowing: Papantla, 1765-1806

    OpenAIRE

    Georgina Moreno Coello

    2012-01-01

    Este trabajo tiene como objeto explorar las estrategias que permitieron la persistencia de la siembra clandestina de tabaco en Nueva España, en particular en la región de Papantla. Analizar las relaciones entre los alcaldes mayores, subdelegados y empleados del monopolio del tabaco, enfatizando la protección informal de la que gozó el cultivo ilegal de parte de las autoridades provinciales y examinar cuál pudo ser el destino del ahorro, así como de las ganancias obtenidas del tabaco ilegal, p...

  7. Tele-asistencia y tele-alarma para adultos mayores: experiencias preliminares en Mexico

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo-Rodriguez

    2013-08-01

    Full Text Available OBJETIVO Analizar el efecto de un programa piloto de tele-asistencia y tele-alarma en la autopercepción del estado de salud de los adultos mayores y conocer la satisfacción y aceptación del programa. METODOS Estudio transversal que incluyó entrevistas a 378 adultos mayores, 294 cuidadores/familiares y 53 profesionales de la salud, realizado en la Ciudad de México en 2010. Variables sociodemográficas, de autopercepción del estado de salud, satisfacción y aceptación del programa se obtuvieron por medio de cuestionario estandarizado. Se realizó análisis descriptivo y se utilizaron pruebas no paramétricas. RESULTADOS Se observaron efectos significativos en la autopercepción del estado de salud, 6,17 (DE 17,9 p < 0,05 puntos por encima de la media. El programa tuvo una buena aceptación por parte de los adultos mayores, de sus cuidadores familiares y de los profesionales de la salud. CONCLUSIONES El programa contribuye a mantener o mejorar la calidad de vida, permite la atención preventiva y es un medio ideal para dar apoyo psicosocial a los adultos mayores.

  8. ¿Estamos preparados para la atención primaria del adulto mayor?

    Directory of Open Access Journals (Sweden)

    Marco Zelada R

    Full Text Available RESUMEN El Ministerio de Salud ha implementado el Modelo de Atención Integral en Salud enfocado por etapas de vida,siendo parte de este,el Programa de Atención al Adulto Mayor.Con el objetivo de conocer el nivel de conocimientos previos sobre geriatría,se realizó una encuesta a los responsables y miembros del equipo interdisciplinario a cargo de dicho programa.Se entrevistó a 73 profesionales de los cuales el 30%recibió conocimientos en el pregrado,y de éstos, 59%la considero como regular o mala;sólo 10%manifestó que basado en sus conocimientos y experiencia tiene la capacidad para manejar problemas de un adulto mayor.Todos consideraron necesaria la capacitación,para ello prefe- rían talleres teórico-prácticos,con pasantías en servicios de geriatría.Los temas de mayor interés fueron hipertensión arterial (84%,depresión (73%,osteoporosis (66%y diabetes (56%.En conclusión,existe una deficiente formación en geriatría entre los responsables de la atención al adulto mayor,debido a una falta de enseñanza en las universidades y pobre capacitación a los profesionales.

  9. Penilaian Gangguan Perilaku Anak Talasemia Mayor dengan Menggunakan The Child Behavior Checklist

    Directory of Open Access Journals (Sweden)

    Mire Riyana

    2018-01-01

    Kesimpulan. Terdapat gangguan perilaku pada anak talasemia mayor. Didapatkan sebagian besar anak dengan gangguan perilaku internal, sementara sebagian besar anak dengan perilaku eksternal dalam kategori normal. Usia anak yang lebih tua memiliki skor CBCL lebih tinggi dan memiliki lebih banyak masalah perilaku.

  10. Changing Course on School Reform: Strategic Organizing around the New York City Mayoral Election

    Science.gov (United States)

    Easton, Billy

    2014-01-01

    New York City's new mayor, Bill de Blasio, represents a dramatic shift from his predecessor Michael Bloomberg in the area of education. Bloomberg was a national trendsetter on market reforms focused on privatization, testing, and competition. De Blasio was elected on an agenda of classroom investments, student supports, parent and community…

  11. Riesgo de deterioro cognitivo en personas mayores de las subregiones de Antioquia, Colombia

    Directory of Open Access Journals (Sweden)

    Angela Segura Cardona

    Full Text Available Resumen En este artículo, se buscó conocer la prevalencia de riesgo de deterioro cognitivo y su relación con factores demográficos, sociales y funcionales en las personas mayores de las subregiones de Antioquia, Colombia. Se trata de un estudio cuantitativo, transversal analítico, con fuente de información primaria. La muestra fue probabilística y se determinó el riesgo de deterioro cognitivo con la escala minimental. Así se encontró que el 83,1% de los mayores presenta algún riesgo de deterioro cognitivo, principalmente las mujeres, y está asociado significativamente con vivir en la subregión del Magdalena Medio y Medellín, tener mayor edad, no tener pareja, no tener escolaridad, tener escasos recursos sociales, no participar en grupos comunitarios, tener mala percepción de la calidad de vida, estar insatisfecho con la salud y tener dependencia funcional para realizar las actividades básicas. Estos resultados permiten orientar los programas de salud pública relacionados con la inclusión de las personas mayores hacia programas educativos, la participación en grupos comunitarios, la tamización constante en los servicios de salud, el fortalecimiento de los recursos sociales y el fomento de la actividad física en la vejez, para lograr un envejecimiento saludable con mejor calidad de vida.

  12. Estrategias de cuidados de las familias con las personas mayores que viven solas

    Directory of Open Access Journals (Sweden)

    Julia Gallo Estrada

    2013-06-01

    Full Text Available Los cambios en el envejecimiento hacen una llamada a trasformar los cuidados dirigidos a las personas mayores que viven solas. Objetivo: Conocer la percepción de la familia sobre el cuidado a los mayores que viven solos. Metodología: Estudio cualitativo mediante análisis de discurso a partir del referencial crítico social y los conceptos de la teoría de Bourdieu. Se realizaron 4 grupos de discusión agrupando a los participantes por género y nivel de instrucción. Resultados: los participantes consideran que la red sociofamiliar puede actuar sobre la discapacidad. Preocupa la manera en la que la persona mayor cubre sus necesidades. Destacan como fundamental el apoyo en la realización de los cuidados. Comparten la idea de que las mujeres mayores se adaptan mejor que los hombres a vivir en soledad. Las mujeres cuidadoras tienden a intervenir precozmente ante los problemas. Los hombres esperan y si pueden delegan. Conclusión: la familia cuestiona los beneficios de la convivencia. La orientación profesional en el cuidado es escasa. Los servicios sociales deben mejorar su accesibilidad.

  13. Leadership of mayors and governors during crises: a systematic review on tasks and effectiveness.

    NARCIS (Netherlands)

    Jong, W.; Dückers, M.L.A.; Velden, P.G. van der

    2016-01-01

    The aim of this article is to provide a systematic review of peer-reviewed literature on leadership tasks and effectiveness of mayors and governors during drastic collective events. A total of 34 peer-reviewed articles met our criteria. They were analysed using the theoretical framework by Boin on

  14. Tipología de compradores online mayores de 55 años

    Directory of Open Access Journals (Sweden)

    Ángel F. Villarejo-Ramos

    2015-12-01

    Full Text Available La edad se considera una de las variables determinantes del riesgo de exclusión social de la población, especialmente con relación al uso de las nuevas tecnologías en general y de Internet en particular. Esto ha incidido en una creciente preocupación por el estudio del colectivo de mayores de 55 años y sus peculiaridades en lo relativo al acceso, uso y aprovechamiento de las TIC (Tecnologías de la Información y la Comunicación. Sin embargo, los esfuerzos se han centrado, mayoritariamente, en el análisis del grupo de mayores como algo homogéneo, lo que ha llevado a establecer sus perfiles de comportamiento en comparación con el de otros grupos de edad. En esta investigación, con una muestra útil de 595 mayores, partimos de la consideración del colectivo como grupo heterogéneo, con distintas características y condiciones de uso de Internet, y proponemos un modelo de clases latentes que nos permite establecer tres perfiles de mayores internautas en función de la utilización de un servicio avanzado de Internet, la compra online.

  15. HBR guides

    CERN Document Server

    Duarte, Nancy; Dillon, Karen

    2015-01-01

    Master your most pressing professional challenges with this seven-volume set that collects the smartest best practices from leading experts all in one place. "HBR Guide to Better Business Writing" and "HBR Guide to Persuasive Presentations" help you perfect your communication skills; "HBR Guide to Managing Up and Across" and "HBR Guide to Office Politics" show you how to build the best professional relationships; "HBR Guide to Finance Basics for Managers" is the one book you'll ever need to teach you about the numbers; "HBR Guide to Project Management" addresses tough questions such as how to manage stakeholder expectations and how to manage uncertainty in a complex project; and "HBR Guide to Getting the Right Work Done" goes beyond basic productivity tips to teach you how to prioritize and focus on your work. This specially priced set of the most popular books in the series makes a perfect gift for aspiring leaders looking for trusted advice. Arm yourself with the advice you need to succeed on the job, from ...

  16. Manifestaciones de violencia intrafamiliar hacia adultos mayores diabéticos. Pinar del Rio, 2012

    Directory of Open Access Journals (Sweden)

    María de la Caridad Casanova Moreno

    Full Text Available Introducción: la violencia contra el adulto mayor es un problema que requiere de sensibilización por parte del equipo de salud para ser visualizado. Objetivo: caracterizar las manifestaciones de violencia intrafamiliar hacia el adulto mayor diabético en un consultorio de la provincia de Pinar del Río. Métodos: se realizó un estudio descriptivo transversal durante el primer semestre del año 2012, en el Consultorio número 10 del Policlínico Universitario "Hermanos Cruz". El universo (U=86 estuvo constituido por el total de adultos mayores diabéticos; la muestra quedó conformada por 52 adultos mayores diabéticos. Las variables estudiadas fueron: edad, sexo, tipo de maltrato recibido, notificación, principal agresor e identificar la necesidad de información sobre el tema. Para la recolección de información se diseñó y aplicó un cuestionario por el equipo de investigación. Se utilizó el porcentaje como medida de resumen. Resultados: el grupo de edad más maltratado fue el de 60 a 69 años, predominando el sexo femenino. Los agresores más cercanos resultaron ser los hijos. La muestra estudiada manifestó que existe una insuficiente divulgación sobre el tema. Conclusiones: en el consultorio donde se realizó la investigación existen manifestaciones de violencia intrafamiliar en adultos mayores diabéticos, a pesar de que la comunidad no la reconoce como uno de sus problemas de salud.

  17. Mayores e Internet: La Red como fuente de oportunidades para un envejecimiento activo

    Directory of Open Access Journals (Sweden)

    Carmen Llorente Barroso

    2015-07-01

    Full Text Available El progresivo envejecimiento de las sociedades ha llevado a los organismos internacionales y europeos a desarrollar programas de envejecimiento activo, capaces de construir una nueva cultura sobre el papel de las personas mayores en la sociedad. Estos incluyen aspectos sociales de carácter comunicacional que, sin embargo, han tenido menos desarrollo investigador que otros más apremiantes, vinculados a aspectos físicos y económicos. Esta investigación atiende precisamente a estas variables comunicacionales, abordando la vinculación de los mayores con Internet y planteándose dos objetivos principales: Conocer las utilidades que tiene Internet para este colectivo y explicar los motivos que convertirían a este medio en una fuente de oportunidades para un envejecimiento activo. Para satisfacerlos, se utiliza una metodología cualitativa que se apoya en el desarrollo de tres grupos de discusión constituidos por entre cinco y seis personas de 56 a 81 años y moderados por un experto. Los resultados obtenidos del análisis cualitativo del contenido en cada discusión indican que Internet es una fuente de oportunidades para los mayores, que pueden aglutinarse en cuatro categorías: informativas, comunicativas, transaccionales y administrativas, y de ocio y entretenimiento. Estas oportunidades optimizan la calidad de vida de los mayores y contribuyen a su envejecimiento activo, si bien, su máximo aprovechamiento precisa de programas de «e-Inclusion» y metodologías que aproximen Internet a los mayores, facilitándoles una formación en competencias digitales.

  18. Uso de medicamentos en adultos mayores de Bogotá, Colombia

    Directory of Open Access Journals (Sweden)

    Carlos Cano-Guitierrez

    Full Text Available Objetivos. Determinar la frecuencia y tipo de medicamentos que utiliza un grupo de adultos mayores que viven en lacapital colombiana, y cuáles son potencialmente inapropiados, con base en los criterios revisados de Beers. Materiales y métodos. Los datos fueron obtenidos del estudio SABE (estudio de salud, bienestar y envejecimiento que se llevó a cabo en áreas urbanas y rurales de Bogotá en el 2012. Se utilizó la prueba U de Mann-Whitney para analizar las diferencias por sexo en los diferentes grupo de edad con relación al número de medicamentos tomados. Resultados. Un total de 1268 (63,4% de los adultos mayores fueron mujeres; entre los participantes, 1514 (75,7% tenían 5 años de educación básica o menos. El promedio de medicamentos tomados en general fue de 3,24 siendo mayor en mujeres (3,50 que en hombres (2,79. Un total de 549 sujetos (27,4% reportaron recibir cinco medicamentos o más. De los medicamentos utilizados, 443 (6,9% eran potencialmente inapropiados de acuerdo con los criterios de Beers. La prevalencia autorreportada de hipertensión fue de 56,9% y para diabetes de 17,5%. Solo 311 sujetos (15,6% no tomaban ningún medicamento. Conclusiones. El uso de medicamentos inapropiados es un problema importante que afecta a los adultos mayores en Bogotá. Estudios adicionales deberán identificar factores que aumentan el riesgo de polifarmacia y uso inapropiado de medicamentos y diseñar intervenciones para prevenir el uso inapropiado de medicamentos entre adultos mayores.

  19. Valoración funcional del adulto mayor relacionado con el abandono familiar.

    Directory of Open Access Journals (Sweden)

    Jenny Fernanda Villarroel Vargas

    2017-03-01

    Full Text Available Introducción: Se estima que entre el 2000 al 2050 la población mundial envejecida ascenderá del 11% al 22 %, con ello el incremento de las diversas enfermedades o trastornos propios de la edad. Objetivo: Establecer la relación entre capacidad funcional del adulto mayor con el abandono familiar en el barrio La Calera Centro, Latacunga, 2015-2016. Métodos: Se realizó un estudio observacional descriptivo de corte trasversal, donde previo consentimiento informado participaron 70 adultos mayores, a quienes se les aplicó escalas para valoración de la capacidad funcional, así como la encuesta para valorar abandono familiar y aspectos sociodemográficos de la población. Para el análisis estadístico se utilizó el test de Chi Cuadrado de Pearson con un nivel de significancia del 0,05. Resultados: Se reportó el abandono en el 75,7% de los adultos mayores y tuvo significancia con respecto a la capacidad funcional y la estructura familiar (p=0,002. Hubo relación  entre capacidad funcional y abandono familiar, así como también predominio de los adultos mayores entre los 65 a 74 años, sexo femenino, sin ninguna actividad laboral y analfabetos. Hubo relación significativa entre capacidad funcional, edades geriátricas y ocupación; y de igual manera entre la estructura familiar y el abandono. La capacidad funcional y la estructura familiar fueron factores asociados al abandono.    Conclusiones: La dependencia del adulto mayor condicionó a diferentes tipos de maltrato, destacando el abandono familiar.

  20. Resiliencia en trabajadores y en residentes de un centro de personas mayores institucionalizadas

    Directory of Open Access Journals (Sweden)

    Inmaculada Méndez

    2015-04-01

    Full Text Available La resiliencia supone un constructo dinámico y multidimensional que alude a la capacidad que tienen las personas para afrontar o recuperarse con éxito de las situaciones adversas. El objetivo del presente estudio ha sido analizar la capacidad de resiliencia en trabajadores y en residentes de un centro de personas mayores institucionalizadas en función de las características sociodemográficas (sexo, edad y estado civil tras la situación adversa por el terremoto ocurrido el Lorca en mayo del 2011. Se ha administrado un cuestionario sociodemográfico desarrollado ad hoc junto a la adaptación de la Escala de Resiliencia de Connor-Davidson (CD-RISC en los sujetos del estudio. Los participantes fueron 20 trabajadores y 34 personas mayores de un centro de personas mayores institucionalizadas de la Región de Murcia (Lorca. La edad media de las personas mayores institucionalizadas fue de 81 años con una desviación típica de 7.68 y la edad media de los cuidadores profesionales fue de 37.85 años y la desviación típica de 9.60. El estudio permite determinar la capacidad de resiliencia atendiendo a características sociodemográficas así como la existencia de diferencias de medias significativas entre la capacidad de tenacidad autoeficacia entre los trabajadores y los residentes del centro de personas mayores lo que permitirá establecer actividades de prevención y/o de intervención.

  1. Analysis and Design of Bi-Directional DC-DC Converter in the Extended Run Time DC UPS System Based on Fuel Cell and Supercapacitor

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2009-01-01

    Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes. The deli......Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes...

  2. Impact of Faults and Protection Methods on DC Microgrids Operation

    DEFF Research Database (Denmark)

    Bayati, Navid; Hajizadeh, Amin; N. Soltani, Mohsen

    2018-01-01

    with the DC Microgrid. This paper evaluates and presents a comprehensive review on the most recent studies in the DC Microgrids protection. Moreover, the fault behavior and characteristics of DC Microgrids, the effect of Constant Power Load (CPL) , and recent DC Microgrid protection methods are reviewed. Also...

  3. Medication Guide

    Science.gov (United States)

    ... Size Small Text Medium Text Large Text Contrast Dark on Light Light on Dark Donate Search Menu Donate What is Glaucoma? Care ... Low Vision Resources Medication Guide Resources on the Web » See All Articles Where the Money Goes Have ...

  4. Zero-voltage DC/DC converter with asymmetric pulse-width modulation for DC micro-grid system

    Science.gov (United States)

    Lin, Bor-Ren

    2018-04-01

    This paper presents a zero-voltage switching DC/DC converter for DC micro-grid system applications. The proposed circuit includes three half-bridge circuit cells connected in primary-series and secondary-parallel in order to lessen the voltage rating of power switches and current rating of rectifier diodes. Thus, low voltage stress of power MOSFETs can be adopted for high-voltage input applications with high switching frequency operation. In order to achieve low switching losses and high circuit efficiency, asymmetric pulse-width modulation is used to turn on power switches at zero voltage. Flying capacitors are used between each circuit cell to automatically balance input split voltages. Therefore, the voltage stress of each power switch is limited at Vin/3. Finally, a prototype is constructed and experiments are provided to demonstrate the circuit performance.

  5. Ultrahigh-density trench cpacitors in silicon and their application to integrated DC-DC conversion

    NARCIS (Netherlands)

    Roozeboom, F.; Bergveld, H.J.; Nowak, K.; Le Cornec, F.; Guiraud, L.; Bunel, C.; Iochem, S.; Ferreira, J.; Ledain, S.; Pieraerts, E.; Pommier, M.

    2009-01-01

    This paper addresses silicon-based integration of passive components applied to 3D integration with dies of other technologies within one package. Particularly, the development of high-density trench capacitors has enabled the realization of small-formfactor DC-DC converters. As illustration, an

  6. Reliability study of high gain DC-DC converters based on RRPP I-IIA ...

    Indian Academy of Sciences (India)

    J DIVYA NAVAMANI

    2018-05-10

    May 10, 2018 ... Energy Storage Modules (ESM), Propulsion Motor Mod- ules (PMM) and ... All Electric Ship (AES) is the best way to power all the loads in the ship ... also used to derive quadratic step down DC-DC converters. [6]. The attractive ...... Exhibition on Ecological Vehicles and Renewable Energies,. TamilNadu ...

  7. Investigation of DC-DC Boost Converter for Reliability of Operational Planning

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Ashouri, Mani; Silva, Filipe Miguel Faria da

    2018-01-01

    of the interests related to reliability is the power semiconductor switches, which are the most vulnerable elements. The failure of one-power switches can reduce the system reliability. Interleaved technique for DC-DC converters is a redundant strategy to improve the reliability, but at the cost of increasing...

  8. A New Sliding Mode Controller for DC/DC Converters in Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    M. Sarvi

    2013-01-01

    Full Text Available DC/DC converters are widely used in many industrial and electrical systems. As DC/DC converters are nonlinear and time-variant systems, the application of linear control techniques for the control of these converters is not suitable. In this paper, a new sliding mode controller is proposed as the indirect control method and compared to a simple direct control method in order to control a buck converter in photovoltaic applications. The solar arrays are dependent power sources with nonlinear voltage-current characteristics under different environmental conditions (insolation and temperature. From this point of view, the DC/DC converter is particularly suitable for the application of the sliding mode control in photovoltaic application, because of its controllable states. Simulations are performed in Matlab/Simulink software. The simulation results are presented for a step change in reference voltage and input voltage as well as step load variations. The simulations results of proposed method are compared with the conventional PID controller. The results show the good performance of the proposed sliding mode controller. The proposed method can be used for the other DC/DC converter.

  9. Switched capacitor DC-DC converter with switch conductance modulation and Pesudo-fixed frequency control

    DEFF Research Database (Denmark)

    Larsen, Dennis Øland; Vinter, Martin; Jørgensen, Ivan Harald Holger

    A switched capacitor dc-dc converter with frequency-planned control is presented. By splitting the output stage switches in eight segments the output voltage can be regulated with a combination of switching frequency and switch conductance. This allows for switching at predetermined frequencies, 31...

  10. Spectral shaping of a randomized PWM DC-DC converter using maximum entropy probability distributions

    CSIR Research Space (South Africa)

    Dove, Albert

    2017-01-01

    Full Text Available maintaining constraints in a DC-DC converter is investigated. A probability distribution whose aim is to ensure maximal harmonic spreading and yet mainaint constraints is presented. The PDFs are determined from a direct application of the method of Maximum...

  11. Common mode noise in three-level DC-DC converters

    CSIR Research Space (South Africa)

    Grobler, Inus

    2009-09-01

    Full Text Available that three-level buck DC-DC converters in general generate much lower common mode currents than conventional two-level buck converters. Further, reductions in common mode currents are achieved by using the improved three-level topologies that have been...

  12. Y-Source Boost DC/DC Converter for Distributed Generation

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    This paper introduces a versatile Y-source boost dc/dc converter intended for distributed power generation, where high gain is often demanded. The proposed converter uses a Y-source impedance network realized with a tightly coupled three-winding inductor for high voltage boosting that is presently...

  13. Experimental study of dynamic behaviors and routes to chaos in DC-DC boost converters

    International Nuclear Information System (INIS)

    Cafagna, D.; Grassi, G.

    2005-01-01

    This paper illustrates an experimental study of a current-programmed DC-DC boost converter, with the aim of investigating possible pathways through which the converter may enter chaos. In particular, based on experimental measurements, it is shown that variations of input voltage and reference current can generate periodic, subharmonic, quasi-periodic and chaotic behaviors

  14. Magnetically integrated high step-up resonant DC-DC converter for distributed photovoltaic systems

    DEFF Research Database (Denmark)

    Vinnikov, Dmitri; Chub, Andrii; Liivik, Elizaveta

    2017-01-01

    In this paper magnetically integrated resonant single-switch quasi-Z-source DC-DC converter is evaluated as a candidate topology for the low-cost photovoltaic microconverter. The derivation of the topology and its basic operation principle are explained. Generalized design guidelines...

  15. Quasiperiodicity and Torus Breakdown in a Power Electronic DC/DC Converter

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai; Soukhoterin, Evgeniy; Mosekilde, Erik

    2007-01-01

    This paper discusses the mechanisms of torus formation and torus destruction in a dc/dc converter with relay control and hysteresis. We establish a chart of the dynamical modes in the input voltage versus load resistance parameter plane. This chart displays several different torus bifurcations...

  16. A DC-DC Converter with Wide Input Voltage Range for Fuel Cell and Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper proposes a novel phase-shift plus duty cycle controlled hybrid bi-directional DC-DC converter based on fuel cells and supercapacitors. The described converter employs two high frequency transformers to couple the half-bridge and full-bridge circuits together in the primary side...

  17. Modelling, Simulation and Construction of a DC/DC Boost Power Converter: A School Experimental System

    Science.gov (United States)

    Silva-Ortigoza, R.; Silva-Ortigoza, G.; Hernandez-Guzman, V. M.; Saldana-Gonzalez, G.; Marcelino-Aranda, M.; Marciano-Melchor, M.

    2012-01-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders…

  18. High-power three-port three-phase bidirectional DC-DC converter

    NARCIS (Netherlands)

    Tao, H.; Duarte, J.L.; Hendrix, M.A.M.

    2007-01-01

    This paper proposes a three-port three-phase bidirectional dc-dc converter suitable for high-power applications. The converter combines a slow primary source and a fast storage to power a common load (e.g., an inverter). Since this type of system is gaining popularity in sustainable energy

  19. Floating high step-down stacked dc-dc converter based on buck-boost cells

    NARCIS (Netherlands)

    Tibola, G.; Duarte, J.L.; Blinov, A.

    2015-01-01

    In some high power dc-dc applications, where high voltage is present, a converter with high step-down ratio is required in order to provide an isolated low power auxiliary supply. This requirement represents a challenge and many topologies are currently being researched. The analysis of a

  20. Magnetically coupled high-gain Y-source isolated DC/DC converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

    2014-01-01

    A new form of magnetically coupled DC/DC converter is proposed for medium power applications (250 W to 2 kW), requiring a high-voltage gain, short inductive charging time and galvanic isolation. The proposed converter can be realised using a unique Y-source impedance network and a two-switch push...

  1. Modelling, simulation and construction of a dc/dc boost power converter: a school experimental system

    International Nuclear Information System (INIS)

    Silva-Ortigoza, R; Marciano-Melchor, M; Silva-Ortigoza, G; Hernández-Guzmán, V M; Saldaña-González, G; Marcelino-Aranda, M

    2012-01-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders the feasible introduction of this equipment in undergraduate laboratories. (paper)

  2. Comparative evaluation of bidirectional dual active bridge DC-DC converter variants

    NARCIS (Netherlands)

    Sfakianakis, G.; Everts, J.; Huisman, H.; Lomonova, E.A.

    2016-01-01

    For the realization of DC-DC converters in automotive industry, the Dual Active Bridge (DAB) converter seems to be a promising choice because of its soft-switching and high-power-density capability. Contrary to the traditional 3 level - 3 level (3-3L) DAB, a 3 level - 5 level (3-5L) DAB can operate

  3. A Novel Single Switch Transformerless Quadratic DC/DC Buck-Boost Converter

    DEFF Research Database (Denmark)

    Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen

    2017-01-01

    A novel quadratic buck-boost DC/DC converter is presented in this study. The proposed converter utilizes only one active switch and can step-up/down the input voltage, while the existing single switch quadratic buck/boost converters can only work in step-up or step-down mode. First, the proposed ...

  4. Single Event Burnout in DC-DC Converters for the LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Claudio H. Rivetta et al.

    2001-09-24

    High voltage transistors in DC-DC converters are prone to catastrophic Single Event Burnout in the LHC radiation environment. This paper presents a systematic methodology to analyze single event effects sensitivity in converters and proposes solutions based on de-rating input voltage and output current or voltage.

  5. Design and Implementation of Digital Current Mode Controller for DC-DC Converters

    DEFF Research Database (Denmark)

    Taeed, Fazel

    to be regulated by a closed-loop controller. The Peak Current Mode Control (PCMC) is one of the most promising control methods for dc-dc converters. It has been known for high bandwidth (speed), and inherent current protection. Increasing the controller bandwidth decreases the output filter size and cost. Analog...

  6. Selection of DC/DC converter for offshore wind farms with MVDC power collection

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

    2017-01-01

    Four DC/DC converters are analyzed and compared with respects to availability, efficiency, ratings, repair costs and power density. Intended application is offshore wind farms with MVDC power collection. The selected topology is a new series resonant converter, which offers 99% efficiency across...

  7. Area-Efficiency Trade-Offs in Integrated Switched-Capacitor DC-DC Converters

    DEFF Research Database (Denmark)

    Spliid, Frederik Monrad; Larsen, Dennis Øland; Knott, Arnold

    2016-01-01

    This paper analyzes the relationship between efficiency and chip area in a fully integrated switched capacitor voltage divider dc-dc converter implemented in 180nm-technology and a 1/2 topology. A numerical algorithm for choosing the optimal sizes of individual components, in terms of power loss...

  8. Research on Two-channel Interleaved Two-stage Paralleled Buck DC-DC Converter for Plasma Cutting Power Supply

    DEFF Research Database (Denmark)

    Yang, Xi-jun; Qu, Hao; Yao, Chen

    2014-01-01

    As for high power plasma power supply, due to high efficiency and flexibility, multi-channel interleaved multi-stage paralleled Buck DC-DC Converter becomes the first choice. In the paper, two-channel interleaved two- stage paralleled Buck DC-DC Converter powered by three-phase AC power supply...

  9. Pulsed dc self-sustained magnetron sputtering

    International Nuclear Information System (INIS)

    Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.

    2008-01-01

    The magnetron sputtering has become one of the commonly used techniques for industrial deposition of thin films and coatings due to its simplicity and reliability. At standard magnetron sputtering conditions (argon pressure of ∼0.5 Pa) inert gas particles (necessary to sustain discharge) are often entrapped in the deposited films. Inert gas contamination can be eliminated during the self-sustained magnetron sputtering (SSS) process, where the presence of the inert gas is not a necessary requirement. Moreover the SSS process that is possible due to the high degree of ionization of the sputtered material also gives a unique condition during the transport of sputtered particles to the substrate. So far it has been shown that the self-sustained mode of magnetron operation can be obtained using dc powering (dc-SSS) only. The main disadvantage of the dc-SSS process is its instability related to random arc formation. In such case the discharge has to be temporarily extinguished to prevent damaging both the magnetron source and power supply. The authors postulate that pulsed powering could protect the SSS process against arcs, similarly to reactive pulsed magnetron deposition processes of insulating thin films. To put this concept into practice, (i) the high enough plasma density has to be achieved and (ii) the type of pulsed powering has to be chosen taking plasma dynamics into account. In this article results of pulsed dc self-sustained magnetron sputtering (pulsed dc-SSS) are presented. The planar magnetron equipped with a 50 mm diameter and 6 mm thick copper target was used during the experiments. The maximum target power was about 11 kW, which corresponded to the target power density of ∼560 W/cm 2 . The magnetron operation was investigated as a function of pulse frequency (20-100 kHz) and pulse duty factor (50%-90%). The discharge (argon) extinction pressure level was determined for these conditions. The plasma emission spectra (400-410 nm range) and deposition

  10. Modeling, Control and Protection of Low-Voltage DC Microgrids

    OpenAIRE

    Salomonsson, Daniel

    2008-01-01

    Current trends in electric power consumption indicate an increasing use of dc in end-user equipment, such as computers and other electronic appliances used in households and offices. With a dc power system, ac/dc conversion within these loads can be avoided, and losses reduced. AC/DC conversion is instead centralized, and by using efficient, fully controllable power-electronic interfaces, high power quality for both ac and dc systems during steady state and ac grid disturbances can be obtaine...

  11. Operation and control of a DC-grid offshore wind farm under DC transmission system faults

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    . Consequently, the protection and control strategies of dc systems need to be established. This paper studies a dc-grid offshore wind farm, where the wind power collection system and power transmission system adopt dc technology. In this paper, the redundancy of the HVDC transmission system under faults...... is studied, and a fault ridethrough strategy for the dc-grid offshore wind farm is proposed. The proposed strategy can effectively minimize the impacts of the power transmission system disturbance on the offshore wind farm, and on the ac grid. A dc-grid offshore wind farm example is simulated with PSCAD....../EMTDC, and the results validate the feasibility of the presented redundancy configuration and operation approach, and the fault ridethrough control strategy....

  12. A suitable model plant for control of the set fuel cell-DC/DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Andujar, J.M.; Segura, F.; Vasallo, M.J. [Departamento de Ingenieria Electronica, Sistemas Informaticos y Automatica, E.P.S. La Rabida, Universidad de Huelva, Ctra. Huelva - Palos de la Frontera, S/N, 21819 La Rabida - Palos de la Frontera Huelva (Spain)

    2008-04-15

    In this work a state and transfer function model of the set made up of a proton exchange membrane (PEM) fuel cell and a DC/DC converter is developed. The set is modelled as a plant controlled by the converter duty cycle. In addition to allow setting the plant operating point at any point of its characteristic curve (two interesting points are maximum efficiency and maximum power points), this approach also allows the connection of the fuel cell to other energy generation and storage devices, given that, as they all usually share a single DC bus, a thorough control of the interconnected devices is required. First, the state and transfer function models of the fuel cell and the converter are obtained. Then, both models are related in order to achieve the fuel cell+DC/DC converter set (plant) model. The results of the theoretical developments are validated by simulation on a real fuel cell model. (author)

  13. Analysis of DC/DC Converter Efficiency for Energy Storage System Based on Bidirectional Fuel Cells

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    interface to the grid. In power electronics, the converter efficiency is characterized at fixed operating voltage for various output power. This type of characterization is not suitable for fuel cells, since as the power from the fuel cell increases, the cell voltage decreases. This paper analyses how......Renewable energy sources are fluctuating depending on the availability of the energy source. For this reason, energy storage is becoming more important and bidirectional fuel cells represent an attractive technology. Fuel cells require highcurrent low-voltage dc-dc or dc-ac converters as power...... the fuel cell I-V characteristics influences the power electronics converter efficiency and their consequence on the overall system. A loaddependent efficiency curve is presented based on experimental results from a 6 kW dc-dc converter prototype including the most suitable control strategy which maximizes...

  14. Envejecimiento poblacional y desigualdades sociales en la mortalidad del adulto mayor en Colombia

    Directory of Open Access Journals (Sweden)

    Juan Carlos Rivillas

    2017-09-01

    Full Text Available Objetivo: analizar la magnitud del envejecimiento poblacional y las desigualdades sociales presentes en la mortalidad del adulto mayor en Colombia. Metodología: estudio ecológico usando datos sub-nacionales de mortalidad, pobreza, barreras de acceso a los servicios de salud y analfabetismo, y de la población adulta mayor para analizar brechas. Se calcularon y compararon tendencias de tres indicadores de impacto: la esperanza de vida (2005-2020, los Índices de envejecimiento y sobre-envejecimiento (2005-2012. Se estimaron tres medidas para resumir la desigualdad absoluta y relativa: el Índice de Desigualdad de la Pendiente (IDP, el Índice Relativo de Desigualdad (IRD de Kunst y Mackenbach, y el Índice de Concentración (IC. Resultados: la proporción de personas mayores será cada vez mayor en Colombia. Las barreras de acceso a los servicios de salud fue la dimensión más inequitativa. Dos patrones de desigualdad fueron identificados: una exclusión marginal en el 60% de los adultos mayores con más ventajas y oportunidades, y un patrón de gradiente lineal presente solo en la incidencia de pobreza. El quintil 3 fue el grupo de departamentos más afectado por la inequidad a lo largo de las dimensiones evaluadas. Discusión: este estudio aporta evidencia sobre patrones de desigualdad en la mortalidad del adulto mayor. A nivel de tendencias, solo fue posible conocer que la brecha ha empeorado en incidencia de pobreza. Conclusiones: las recomendaciones se centran en cinco áreas de acción, para lograr un contexto deseable para el abordaje del envejecimiento poblacional y la reducción de las desigualdades, como desafíos del sistema de salud y de protección social, y que pueden socavar la realización progresiva de la cobertura universal en salud y el logro de los objetivos de desarrollo sostenible para 2030.

  15. Sobrecarga y calidad de vida del cuidador principal del adulto mayor

    Directory of Open Access Journals (Sweden)

    Jack Roberto Silva Fhon

    2016-09-01

    Full Text Available Objetivo: Determinar la sobrecarga de trabajo y la calidad de vida del cuidador principal del adulto mayor atendido en un consultorio de geriatría. Metodología: Estudio cuantitativo, descriptivo, de corte transversal, realizado con 183 adultos mayores y sus respectivos cuidadores atendidos en un consultorio de geriatría. Para la recolección de los datos, fueron utilizados los instrumentos de perfil demográfico para el adulto mayor y su cuidador Escala de Zarit y The Medical Outcomes Study 36-item (sf-36. El análisis se realizó por medio de la estadística descriptiva y de la prueba de correlación de Spearman, con un nivel de significancia de p ≤ 0,05. Resultados: En los adultos mayores, hubo predominio del sexo masculino; la edad promedio fue de 74,8 años y estaban casados/as. En los cuidadores, predominó el sexo femenino; la edad promedio fue de 44,3 años. El total de cuidadores tenían estudios superiores, estaban casados/as y eran hijos/as de los adultos mayores. Según la evaluación con la Escala de Zarit, el 18,1% presentó algún tipo de sobrecarga; en cuanto a la calidad de vida, las dimensiones con menor puntuación fueron Salud general, Salud mental y Vitalidad. Se obtuvo una correlación inversa entre la puntuación total de la Escala de Zarit y todas las dimensiones de la calidad de vida. Conclusión: Se observó que el desgaste de la calidad de vida se debe a la sobrecarga en el cuidado del adulto mayor. Por lo tanto, se hace necesario acompañar el estado de salud de los cuidadores con la finalidad de prevenir alteraciones físicas y mentales.

  16. Perfil de los adultos mayores usuarios de atención primaria

    Directory of Open Access Journals (Sweden)

    Fabianne de Jesus Dias de Sousa

    2017-05-01

    Full Text Available Introducción: Las proyecciones indican que Brasil será el sexto país del mundo con el mayor número de adultos mayores. El objetivo de este estudio fue caracterizar las condiciones de perfil y de vida socio-demográficos y de salud de los usuarios adultos mayores de la atención primaria de un municipio en la región amazónica del Brasil. Es oportuno porque el envejecimiento de la población está creciendo rápidamente, especialmente en países en desarrollo como el Brasil. Materiales y Métodos: Estudio transversal con una muestra de 441 individuos con edad inferior a 60 años de la población de usuarios de la atención básica en el municipio de Benevides, en la Amazonia brasileña. Os datos fueron obtenidos a través del Elder notebook, un protocolo clínico del Ministerio de la Salud. La prueba del chi-cuadrado con un nivel de significancia de 5% para explorar fue utilizada las asociaciones entre las variables de las condiciones de salud y de vida, y las variables socio-demográficas. Resultados: Se presentaron un perfil predominantemente joven adultos mayores (46.0%, que no practican actividad física (p<0.02, con condiciones crónicas y uso de drogas para inducir el sueño (p<0.05. Discusión y Conclusiones: El perfil de vida desfavorable y de salud encontrados en adultos mayores exige la adopción de medidas reforzadas, sobre la salud y los presupuestos de atención integral como un desafío para efectuar la colocación de sus necesidades, principalmente por la enfermería, en la Atención Básica de Salud en áreas más necesitadas de la región amazónica. Cómo citar este artículo: Sousa FJD, Andrade FS. Perfil de los adultos mayores usuarios de atención primaria. Rev Cuid. 2017; 8(2: 1573-81. http://dx.doi.org/10.15649/cuidarte.v8i2.376

  17. Research borehole drilling activity for boreholes DH-18, DH-19, DC-12, DC-13, DC-14, DC-15, and deepening of existing borehole DC-7

    International Nuclear Information System (INIS)

    1979-09-01

    This report is an environmental evaluation of the impacts of proposed borehole drilling activities at the Hanford Site, northwest of Richland, Washington. The proposed action is to drill six research boreholes ranging in depth from 137 to 1372 meters (m) [250 to 4500 +- feet (ft)]. In addition, an existing borehole (DC-7) will be extended from 1249 to 1524 m (4099 to 5000 +- ft). The purpose of the US Department of Energy's (DOE) borehole drilling activities is to collect data on in situ rock formations that are considered potentialy suitable for nuclear waste repositories. The technical program efforts necessary to identify and qualify specific underground waste facility sites in candidate rock formations include geologic and hydrologic studies (seismicity and tectonics, rock structure and stratigraphy, lithology, etc.). Borehole drilling is an integral part of the geological studies and is essential to a thorough understanding of potentially suitable geologic formations. The purpose of the proposed drilling activities is to obtain data for evaluating Columbia River basalts that are being evaluated by the National Waste Terminal Storage (NWTS) Program to determine their suitability potential for nuclear waste repositories. Unavoidable impact to the environment is limited primarily to the clearing of land needed for access and drilling operations. Considerations exercised during site preparation, drilling, and subsequent site restoration will limit modification of the natural environment to the minimum required for accomplishment of test objectives

  18. Vitamina B12, Acido Fólico y Función Mental en Adultos Mayores

    OpenAIRE

    Meertens-R, Lesbia; Solano-R, Liseti

    2005-01-01

    Los adultos mayores constituyen un grupo de población vulnerable a cuadros de deficiencias de nutrientes específicos como la vitamina B12 y el ácido fólico, íntimamente ligados al deterioro de las funciones mentales, en especial, del área cognitiva. El objetivo de este estudio fue determinar indicadores del estado de vitamina B12 y ácido fólico y asociarlos a la evaluación de la función mental de 53 adultos mayores de 60 años de edad, residenciados en un hogar geriátrico. Se evaluó consumo di...

  19. OPTIMALISASI PELAKSANAAN KURIKULUM SISTEM MAYOR-MINOR PROGRAM PENDIDIKAN SARJANA INSTITUT PERTANIAN BOGOR

    Directory of Open Access Journals (Sweden)

    Sutoro Sutoro

    2016-09-01

    Full Text Available This study aims to 1 evaluate the implementation of major-minor curriculum system in IPB Undergraduate Program, 2 identify factors leading to less optimized implementation of the major-minor curriculum system in IPB Undergraduate Program and 3 design strategies to optimize the implementation of the major-minor curriculum system in IPB Undergraduate Program. Analytical Hierarchy Process was utilized as the method of study. The results showed that the implementation of the major-minor curriculum system in IPB Undergraduate Program is still considered to be less optimal. Factors influencing the implementation of the major-minor curriculum system in IPB Undergraduate Program, according to its priority, include: 1 the availability of competent and committed teaching staffs, 2 the availability of adequate lecturing facilities and infrastructure, 3 the availability of lecture schedule to accommodate students who choose minor curriculum, and 4 the availability of reliable and IT-based Academic Information System (SIMAK. Strategies to optimize the implementation of major-minor curriculum system in IPB Undergraduate Program, according to its priority, include; 1 improving the competence and commitment of teaching and educational staffs, 2 increasing the commitment of departments and faculties to facilitate the fulfillment of minor  curriculum schedules, 3 providing adequate facilities and infrastructure to implement the major and minor curriculum system, and 4 providing lecture schedules that can accommodate the needs of students who choose minor curriculum.Keywords: analytical hierarchy process, optimization, major-minor curriculum systemABSTRAKPenelitian ini bertujuan 1 mengevaluasi pelaksanaan kurikulum sistem mayor-minor pada Program Pendidikan Sarjana IPB, 2 mengidentifikasi faktor-faktor yang menyebabkan kurang optimalnya pelaksanaan kurikulum sistem mayor-minor pada Program Pendidikan Sarjana IPB dan 3 merancang strategi untuk mengoptimalkan

  20. Fuzzy logic and information fusion to commemorate the 70th birthday of Professor Gaspar Mayor

    CERN Document Server

    Sastre, Joan

    2016-01-01

    This book offers a timely report on key theories and applications of soft-computing. Written in honour of Professor Gaspar Mayor on his 70th birthday, it primarily focuses on areas related to his research, including fuzzy binary operators, aggregation functions, multi-distances, and fuzzy consensus/decision models. It also discusses a number of interesting applications such as the implementation of fuzzy mathematical morphology based on Mayor-Torrens t-norms. Importantly, the different chapters, authored by leading experts, present novel results and offer new perspectives on different aspects of Mayor’s research. The book also includes an overview of evolutionary fuzzy systems, a topic that is not one of Mayor’s main areas of interest, and a final chapter written by the Spanish pioneer in fuzzy logic, Professor E. Trillas. Computer and decision scientists, knowledge engineers and mathematicians alike will find here an authoritative overview of key soft-computing concepts and techniques.

  1. RELACIÓN MÉDICO PACIENTE: DERECHOS DEL ADULTO MAYOR

    Science.gov (United States)

    Barrantes-Monge, Melba; Rodríguez, Eduardo; Lama, Alexis

    2009-01-01

    Existen prejuicios en relación con la vejez, incluso entre los profesionales que se dedican a la gerontología. Uno común y peligroso es considerar que los viejos son todos enfermos o discapacitados. La relación médico-paciente es la piedra angular de la práctica y ética médicas. Para alcanzar el respeto por los adultos mayores es necesaria una medicina prudente, basada en una práctica en la cual la reflexión ética y clínica pueda contribuir. Esto último es posible si se hacen valer los derechos del adulto mayor, en particular como paciente para la toma de decisiones. PMID:20379380

  2. La obesidad en las personas mayores, un problema de salud pública

    OpenAIRE

    Abellán García, Antonio

    2016-01-01

    La obesidad es un serio problema de salud pública. Se suele medir utilizando el Índice de Masa Corporal. En España, un 23,6% de las personas mayores (65 y más años) tiene obesidad, y otro 45,0% sobrepeso, según la última Encuesta Europea de Salud (2014). Sólo un 30,0% está en un peso normal. En el resto de adultos también se observa esta circunstancia. Es decir, en España existe un problema de sobrepeso y obesidad, especialmente entre los mayores y estas cifras son peores que la media de la ...

  3. Burnout e intenciones de jubilación anticipada entre empleados mayores - Burnout and early retirement intentions among older employees

    NARCIS (Netherlands)

    Henkens, C.J.I.M.; Leenders, M.

    2009-01-01

    El tema central de este artículo es la jubilación y el burnout de los empleados mayores. Analizamos si existe una relación entre las dimensiones de agotamiento emocional y despersonalización características del burnout y las intenciones de jubilación de los empleados mayores. Asimismo, se investiga

  4. Attitudes and Perceptions of Vocational Education in New York City: Implications for the Mayor's School Reform Initiative

    Science.gov (United States)

    Green, Rupert

    2012-01-01

    Under-performing New York City (NYC) schools precipitated Mayor Michael Bloomberg's decision to advance a vocational education initiative. The initiative was to address the problem of the many city high school graduates lacking both the skills for gainful employment and the academic preparedness to pursue higher education. The mayor's initiative…

  5. Efectos contextuales asociados a la variabilidad del riesgo de depresión en adultos mayores, Antioquia, Colombia, 2012

    Directory of Open Access Journals (Sweden)

    Doris Cardona

    2015-03-01

    Conclusiones. El municipio y la manzana de residencia aportaron 10 % de la variabilidad total del riesgo de depresión en los adultos mayores. Esta información es importante para fomentar la participación y adhesión de los adultos mayores a grupos comunitarios.

  6. Three phase full wave dc motor decoder

    Science.gov (United States)

    Studer, P. A. (Inventor)

    1977-01-01

    A three phase decoder for dc motors is disclosed which employs an extremely simple six transistor circuit to derive six properly phased output signals for fullwave operation of dc motors. Six decoding transistors are coupled at their base-emitter junctions across a resistor network arranged in a delta configuration. Each point of the delta configuration is coupled to one of three position sensors which sense the rotational position of the motor. A second embodiment of the invention is disclosed in which photo-optical isolators are used in place of the decoding transistors.

  7. DCMF: DC & Microformats, a good marriage

    OpenAIRE

    Méndez Rodríguez, Eva María; Siches, Arnau; López, Leandro M.; Bravo, Alejandro G.

    2008-01-01

    This report introduces the Dublin Core Microformats (DCMF) project, a new way to use the DC element set within X/HTML. The DC microformats encode explicit semantic expressions in an X/HTML webpage, by using a specific list of terms for values of the attributes “rev” and “rel” for and elements, and “class” and “id” of other elements. Microformats can be easily processed by user agents and software, enabling a high level of interoperability. These characteristics are crucial for the growing n...

  8. Implementation of hierarchical control in DC microgrids

    DEFF Research Database (Denmark)

    Jin, Chi; Wang, Peng; Xiao, Jianfang

    2014-01-01

    of Technology, Singapore. The coordination control among multiple dc sources and energy storages is implemented using a novel hierarchical control technique. The bus voltage essentially acts as an indicator of supply-demand balance. A wireless control is implemented for the reliable operation of the grid....... A reasonable compromise between the maximum power harvest and effective battery management is further enhanced using the coordination control based on a central energy management system. The feasibility and effectiveness of the proposed control strategies have been tested by a dc microgrid in WERL....

  9. RF and dc desensitized electroexplosive device

    Science.gov (United States)

    Krainiak, John W.; Speaks, Paul D.; Cornett, Michael S.

    1989-07-01

    This patent application relates to electroexplosive devices (EEDs) such as detonators, blasting caps and squibs, in particular to a method and device for desensitizing EEDs to electromagnetic radiation and electrostatic charges with the added ability to desensitize the device to essentially dc currents. An insensitive electroexplosive device to electrically ignite explosive is disclosed. This device is inherently immune to radio frequency (RF) radiation, and also provides protection against dc or very low frequency RF induced by arcing. A central feature is use of zeners and capacitors to form a reactively balanced bridge circuit. When constructed in semiconductor form, as described in this application, the device is capable of incorporation in small caliber ordnance.

  10. DC Motor Drive with PFC Rectifier

    Directory of Open Access Journals (Sweden)

    Lascu Mihaela

    2008-05-01

    Full Text Available The goal of this work is to study theperformances of a hybrid controller used to controlDC Motor drive with a single-phase power factorcorrection rectifier. This study is made usingcomputer simulation (Simulink. The first part isdevoted to the control system of the DC Motors. Inthe second part, the design of the hybrid controllerwill be presented. The third part is the design ofthe fast response single-phase boost power factorcorrection rectifier. The last parts are devoted tosimulation and experimental results.

  11. Nivel de sobrecarga en los cuidadores informales primarios de adultos mayores hospitalizados

    OpenAIRE

    Diaz Jardon, Gerardo

    2014-01-01

    México vive una transición demográfica un perfil caracterizado por edades avanzados, de acuerdo con el Instituto Nacional de Geografía y Estadística, en 2010, el grupo de población de personas mayores de 60 años es de 10.1 millones lo que representa el 9 % de acuerdo con ls proyecciones demográficas del Consejo Nacional de Poblacion

  12. Colegiales mayores de Castilla en la Italia española

    Directory of Open Access Journals (Sweden)

    Pere MOLAS RIBALTA

    2009-12-01

    Full Text Available La importancia de los seis Colegios Mayores de las universidades castellanas de Salamanca, Valladolid y Alcalá en la selección del personal judicial y político de la Monarquía española de los siglos XVI, XVII y XVIII es un hecho histórico bien conocido en sus líneas generales y actualizado por nuevas y rigurosas investigaciones.

  13. Estereotipos negativos hacia la vejez en personas mayores de Latinoamérica

    Directory of Open Access Journals (Sweden)

    Viviana X. Lasagni Colombo

    2014-03-01

    Full Text Available Introducción: Los objetivos del estudio se centran en investigar la presencia de estereotipos hacia la vejez en adultos mayores de diez países de Latinoamérica. Comparar el nivel de estereotipos entre países y evaluar la influencia de variables socio-demográficas en la formación de estereotipos. Metodología: Se realizó un estudio descriptivo transversal en adultos mayores de 60 a 70 años (N: 965 residentes en diez países de Latinoamérica. Se aplicó el Cuestionario de Estereotipos Negativos hacia la Vejez (CENVE y se estudió las posibles asociaciones entre variables socio demográficas y los factores del CENVE a través del análisis de varianzas (ANOVA. Los resultados demuestran que existen estereotipos negativos hacia la vejez en las personas mayores siendo más baja la presencia de estos en el factor motivacional. Se comprobó la relación significativa con variables “ocupación” y “nivel de escolaridad” y se corroboró la diferencia en la presencia de estereotipos negativos hacia la vejez entre los países que conforman este estudio. Conclusión: existen estereotipos negativos hacia la vejez en las personas mayores con diferencias entre grupos de países fundamentalmente por las condiciones sociosanitarias, educativas y económicas por las que atraviesan. El nivel de escolaridad y la situación socioeconómica influyen en la construcción de estereotipos negativos hacia la vejez.

  14. Prevalencia de hipertensión en adultos mayores de Costa Rica

    Directory of Open Access Journals (Sweden)

    Rosero-Bixby, Luis

    2007-07-01

    Full Text Available Este artículo estima la prevalencia de hipertensión (controlada y con o sin diagnóstico previo entre los adultos mayores costarricenses. Valora los problemas de medición y explora los factores asociados con la enfermedad. Se utilizan datos de una muestra nacional representativa del proyecto CRELES: “Costa Rica: Estudio de Longevidad y Envejecimiento Saludable”. Se realizaron dos mediciones de la presión arterial con monitores digitales a una muestra de 3000 adultos y se registró el auto reporte de la enfermedad y el uso de medicamentos antihipertensivos. La segunda medición resultó en valores significativamente menores tanto para la presión diastólica como para la sistólica. No se detectaron sesgos en la medición realizada por entrevistador ni por trimestre de trabajo de campo. El 59% de los adultos mayores del país sufre de hipertensión (HTA. La prevalencia es mayor entre las mujeres que entre los hombres. El 16% de todos los adultos mayores no tenían diagnóstico previo de HTA pero en nuestras mediciones resultaron con HTA. Los principales co-factores de HTA identificados en este artículo son: edad, estar asegurado, el índice de masa corporal, los antecedentes familiares, tener menos de 6 años de educación formal, ser fumador activo y consumir más de 3000 calorías al día.

  15. Stability analysis of a high-step-Up DC grid-connected two-stage boost DC-DC converter

    Directory of Open Access Journals (Sweden)

    El Aroudi A.

    2014-01-01

    Full Text Available High conversion ratio switching converters are used whenever there is a need to step-up dc source voltage level to a much higher output dc voltage level such as in photovoltaic systems, telecommunications and in some medical applications. A simple solution for achieving this high conversion ratio is by cascading different stages of dc-dc boost converters. The individual converters in such a cascaded system are usually designed separately applying classical design criteria. However these criteria may not be applicable for the complete cascaded system . This paper first presents a glimpse on the bifurcation behavior that a cascade connection of two boost converters can exhibit. It is shown that the desired periodic orbit can undergo period doubling leading to subharmonic oscillations and chaotic regimes. Then, in order to simplify the analysis the second stage is considered as constant current sink and design-oriented analysis is carried out to obtain stability boundaries in the parameter space by taking into account slope interactions between the state variables in the two-different stages.

  16. The copal of the Chichen Itza offerings and of the Templo Mayor of Tenochtitlan

    International Nuclear Information System (INIS)

    Montufar L, A.; Gutierrez W, C.E.; Mendoza A, D.; Torres M, A.

    2006-01-01

    Literature from the post conquest shows that the Mayans used copal resins in their religious celebrations and ceremonial rites, specially as a sahumerio material. Historical precedents have been fully documented, establishing its use in the calendar ceremonies performed by the Aztecs towards their agricultural practices, mainly for the corn crop; and that according to the registries of sacred figures of their gods, they were made out of copal resin. Abundant fragments of this resin were found in a number of offerings at the digging of the Templo Mayor of Tenochtitlan. These facts indicate the intensive use of the copal as a link with divinities of life, maintenance and fertility, among many other aspects of existence, as stated by the Mexicas cosmos view. In order to determine the possible origin of the different types of copal, small samples were analyzed by infrared spectroscopy, both from Chichen Itza and the pre hispanic from Templo Mayor of Tenochtitlan. Results show a great similarity between each absorption band, the one from Templo Mayor and the modern sample Bursera bipinnata and the one from Chichen Itza and the modem resin of Protium copal. This suggests that the pre hispanic copal form Chichen Itza was obtained from the Protium copal tree. (Author)

  17. Cuidado popular de familias con un adulto mayor sobreviviente del primer accidente cerebrovascular

    Directory of Open Access Journals (Sweden)

    Lucero López-Díaz

    2016-01-01

    Full Text Available Introducción: el accidente cerebrovascular afecta a numerosas personas en el mundo y se constituye en la principal causa de muer- te. Los sobrevivientes pueden padecer discapacidad y sufrir modificaciones en las actividades cotidianas. La familia es el principal apoyo del sobreviviente y al ser parte de una misma cultura, construye acciones de cuidado en búsqueda del bienestar. Objetivo: describir las acciones del cuidado popular de las familias con un adulto mayor sobreviviente del primer accidente cerebrovascular. Método: estudio etnográfico, con observación participante y entrevistas en profundidad. Participaron siete familias bogotanas (siete adultos mayores entre los dos y diez meses posteriores al primer accidente cerebrovascular y los siete cuidadores principales respectivos. Resultados: cuidadores y adulto mayor comparten acciones de cuidado para la recuperación, relacionadas con la alimentación, el cuidado personal y la ingesta de medicamentos permeadas por la creencia religiosa, fuente de soporte y vínculo afectivo. Conclusión: conocer el cuidado popular de esta población posibilita proponer acciones culturalmente congruentes con sus valores y creencias para potencializar las ca- pacidades familiares e intermediar en los procesos de tratamiento.

  18. El mundo afectivo de adultos mayores en situación de dependencia y sus cuidadores

    Directory of Open Access Journals (Sweden)

    Juana Rosa Hidalgo-Martinola

    2015-12-01

    Full Text Available El objetivo del presente trabajo es caracterizar la relación interpersonal entre cuidadores informales primarios y adultos mayores en situación de dependencia, a partir, de un estudio de casos múltiples. Se empleó la metodología cualitativa y el método etnometodológico. Se seleccionaron tres casos, por la presencia de diferentes grados de dependencia en los adultos mayores. Las técnicas empleadas fueron: entrevista en profundidad, escala de evaluación funcional y la observación abierta.Los principales resultados muestran que las relaciones interpersonales entre un cuidador informal primario y un adulto mayor en situación de dependencia, actualizan la historia de la relación anterior, generando vivencias de frustración y/o satisfacción en función de la dinámica pasada. Este proceso primario adquiere más trascendencia que las propias habilidades comunicativas en la relación y marcan una vivencia de la relación, que en algunos casos, se diferencia de la vivencia de la labor del cuidado.

  19. Salud y calidad de vida de cuidadores familiares y profesionales de personas mayores dependientes: estudio comparativo

    Directory of Open Access Journals (Sweden)

    Noelia Flores

    2014-08-01

    Full Text Available El trabajo que se presenta tiene como objetivo analizar las semejanzas y diferencias en la salud y en la calidad de vida de los cuidadores familiares y profesionales que atienden a personas mayores en situación de dependencia. Concretamente se presentan los resultados obtenidos tras la evaluación de 600 cuidadores de los cuales un 33,83% son familiares y un 66,17% son profesionales, a quienes se evaluó la carga o estrés experimentado, la salud física y psicológica y la calidad de vida general, laboral, familiar y social. Los resultados obtenidos indican que existen diferencias entre ambos grupos de cuidadores. Los familiares dedicados al cuidado presentan mayores niveles de sobrecarga y tienen una peor salud física y psicológica como consecuencia de la atención prestada al dependiente. Los cuidadores profesionales experimentan una mayor satisfacción con la vida en general y con otros factores como el trabajo, la familia y las relaciones sociales. Finalmente se justifica la necesidad de poner en marcha intervenciones de mejora de la salud de los cuidadores

  20. Patronage or Signaling: How Mayors Use City Payroll to Stay in Office

    Directory of Open Access Journals (Sweden)

    Vobolevičius Vincentas

    2016-12-01

    Full Text Available Several studies on municipal hiring decisions have indicated that when a city’s payroll grows, its mayor’s re-election prospects are likely to improve. It is not clear, however, if such an effect is attributable to patronage-driven, or signaling-driven, behavior of the incumbents. The difference is important: patronage leads to inefficient public administration, while signaling can produce political business cycles. In this paper, I propose some key electoral implications of patronage-driven and signaling-driven hiring, and verify them with data on local elections in Bulgaria (2015 and 2011 and in Poland (2014. I find that a large municipal workforce has a negative overall effect on mayors’ re-election. Importantly, the impact of city payroll varies with incumbents’ partisanship (strongly negative for mayors representing the economic right, neutral for independent mayors, positive for ex-communist mayors and does not depend on the duration of incumbent’s tenure. These findings strongly support the patronage-driven explanation of Eastern Europe’s local political economy.

  1. MÉXICO Y ESTADO DE GUANAJUATO: TRANSFERENCIAS INTERGENERACIONALES HACIA LOS ADULTOS MAYORES*

    Science.gov (United States)

    Montes de Oca, Verónica; Hebrero, Mirna

    2017-01-01

    RESUMEN En México, las transferencias formales e informales destinadas al apoyo de las personas adultas mayores son diversificadas. En este documento se analizan la tendencia nacional y los resultados de un estudio centrado en la entidad federativa de Guanajuato. La distribución de los apoyos confirma que las transferencias hechas por el sistema de seguridad social tienen un sesgo urbano y que las transferencias formales del gobierno federal se orientan a las áreas menos urbanizadas, particularmente las zonas rurales. A pesar de las transferencias formales (esporádicas e insuficientes), las necesidades económicas y de salud de las personas mayores persisten y ello lleva a que sus familiares realicen transferencias informales de naturaleza ascendente. En México —y más concretamente en Guanajuato— el apoyo de quienes residen con la persona mayor tiene un significativo peso, y lo contrario sucede con el de quienes han migrado. A partir de este material, se analiza el rol que, de acuerdo a su cohorte y su condición migratoria, desempeñan los descendientes. En todo caso, queda de manifiesto que, en cada entidad nacional, las dinámicas de transferencias intergeneracionales son de diversos tipos. PMID:29375179

  2. Exceso de peso y discapacidad en las personas mayores de la Argentina

    Directory of Open Access Journals (Sweden)

    Malena Monteverde

    2015-01-01

    Full Text Available El objetivo del presente trabajo es analizar la relación entre el exceso de peso y la condición de discapacidad en las personas mayores de la Argentina y evaluar en qué medida podría estar operando algún factor protector que reduzca o atenúe el efecto del exceso de peso sobre la pérdida de capacidades funcionales en las personas mayores de 64 años. Para ello se utilizan los microdatos de la Encuesta Nacional de Factores de Riesgo 2009. Con el objeto de medir la asociación entre sobrepeso, obesidad y la condición de discapacidad, así como la interacción de la condición de peso y la edad, se estiman modelos de regresión logística. Los resultados indican que, si bien el sobrepeso y la obesidad tendrían un efecto neto positivo sobre la presencia de discapacidades, este sería menor entre las personas de 64 años y más. Los resultados sugieren que entre las personas mayores existe algún factor protector, que si bien no revierte la relación directa entre exceso de peso y discapacidad, parece atenuarla.

  3. Design and modelling of high gain DC-DC converters for fuel cell hybrid electric vehicles

    Science.gov (United States)

    Elangovan, D.; Karthigeyan, V.; Subhanu, B.; Ashwin, M.; Arunkumar, G.

    2017-11-01

    Transportation (Diesel and petrol internal combustion engine vehicles) approximately contributes to 25.5% of total CO2 emission. Thus diesel and petrol engine vehicles are the most dominant contributors of CO2 emission which leads global warming which causes climate change. The problem of CO2 emission and global warming can be reduced by focusing on renewable energy vehicles. Out of the available renewable energy sources fuel cell is the only source which has reasonable efficiency and can be used in vehicles. But the main disadvantage of fuel cell is its slow response time. So energy storage systems like batteries and super capacitors are used in parallel with the fuel cell. Fuel cell is used during steady state vehicle operation while during transient conditions like starting, acceleration and braking batteries and super capacitors can supply or absorb energy. In this paper a unidirectional fuel cell DC-DC converter and bidirectional energy storage system DC-DC converter is proposed, which can interface dc sources at different voltage levels to the dc bus and also it can independently control the power flow from each energy source to the dc bus and vice versa. The proposed converters are designed and simulated using PSIM version 9.1.1 and gate pulse pattern, input and output voltage waveforms of the converters for steady state operation are studied.

  4. Homopolar dc motor and trapped flux brushless dc motor using high temperature superconductor materials

    Science.gov (United States)

    Crapo, Alan D.; Lloyd, Jerry D.

    1991-03-01

    Two motors have been designed and built for use with high-temperature superconductor (HTSC) materials. They are a homopolar dc motor that uses HTSC field windings and a brushless dc motor that uses bulk HTSC materials to trap flux in steel rotor poles. The HTSC field windings of the homopolar dc motor are designed to operate at 1000 A/sq cm in a 0.010-T field. In order to maximize torque in the homopolar dc motor, an iron magnetic circuit with small air gaps gives maximum flux for minimum Ampere turns in the field. A copper field winding version of the homopolar dc motor has been tested while waiting for 575 A turn HTSC coils. The trapped flux brushless dc motor has been built and is ready to test melt textured bulk HTSC rings that are currently being prepared. The stator of the trapped flux motor will impress a magnetic field in the steel rotor poles with warm HTSC bulk rings. The rings are then cooled to 77 K to trap the flux in the rotor. The motor can then operate as a brushless dc motor.

  5. Guide device

    International Nuclear Information System (INIS)

    Brammer, C.M. Jr.

    1977-01-01

    Disclosed is a fuel handling guide tube centering device for use in nuclear reactors during fuel assembly handling operations. The device comprises an outer ring secured to the flange of a nuclear reactor pressure vessel, a rotatable table rotatably coupled to the outer ring, and a plurality of openings through the table. Truncated locating cones are positioned in each of the openings in the table, and the locating cones center the guide tube during fuel handling operations. The openings in the table are located such that each fuel assembly in the nuclear core may be aligned with one of the openings by a suitable rotation of the table. The locating cones thereby provide alignment between the fuel handling mechanism located in the guide tube and the individual fuel assemblies of the cone. The need for a device to provide alignment is especially critical for floating nuclear power plants, where wave motion may exist during fuel handling operations. 5 claims, 4 figures

  6. Comparison of solar panel cooling system by using dc brushless fan and dc water

    International Nuclear Information System (INIS)

    Irwan, Y M; Leow, W Z; Irwanto, M; M, Fareq; Hassan, S I S; Amelia, A R; Safwati, I

    2015-01-01

    The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer. (paper)

  7. Significado de la calidad de vida del adulto mayor para sí mismo y para su familia

    Directory of Open Access Journals (Sweden)

    Martha Vera

    2007-09-01

    Full Text Available Objetivo: Comprender el significado que la expresión lingüística ‘calidad de vida del adulto mayor’ tiene para el adulto mayor y para su familia. Diseño: Estudio cualitativo, descriptivo, interpretativo - comprensivo, fundamentado en la Teoría de las Representaciones Sociales. Lugar: Asentamiento Humano Laura Caller, en Los Olivos. Participantes: Adultos mayores y sus respectivos grupos familiares. Métodos: Las técnicas e instrumentos utilizados fueron la observación, entrevista a profundidad y grupos focales; guía de observación y dos cuestionarios con ocho preguntas norteadoras, previamente validados. Principales medidas de resultados: Significado de calidad de vida para el adulto mayor y para la familia. Resultados: Participaron dieciséis adultos mayores con sus respectivos grupos familiares, entre 2004 y 2006. Los discursos a través de la ‘objetivación’ y el ‘anclaje’ y los análisis general, ideográfico-axial y nomotético-selectivo permitieron la emergencia de cuatro representaciones sociales: a conocimiento sobre la vejez y ser un adulto mayor; b elementos principales y secundarios del significado de calidad de vida del adulto mayor; c valores y actitudes del adulto mayor y familia sobre la calidad de vida; y, d necesidades del adulto mayor como ser social y la calidad de vida. Conclusiones: Para el adulto mayor, calidad de vida significa tener paz y tranquilidad, ser cuidado y protegido por la familia con dignidad, amor y respeto, y tener satisfechas como ser social sus necesidades de libre expresión, decisión, comunicación e información. Para la familia, que el adulto mayor satisfaga sus necesidades de alimentación, vestido, higiene y vivienda.

  8. Transition towards DC micro grids: From an AC to a hybrid AC and DC energy infrastructure

    Directory of Open Access Journals (Sweden)

    Evi Ploumpidou

    2017-12-01

    Full Text Available Our electricity is predominantly powered by alternating current (AC, ever since the War of Currents ended in the favor of Nicola Tesla at the end of the 19th century. However, lots of the appliances we use, such as electronics and lights with light-emitting diode (LED technology, work internally on direct current (DC and it is projected that the number of these appliances will increase in the near future. Another contributor to the increase in DC consumption is the ongoing electrification of mobility (Electric Vehicles (EVs. At the same time, photovoltaics (PV generate DC voltages, while the most common storage technologies also use DC. In order to integrate all these appliances and technologies to the existing AC grid, there is a need for converters which introduce power losses. By distributing DC power to DC devices instead of converting it to AC first, it is possible to avoid substantial energy losses that occur every time electricity is converted. This situation initiated the concept for the implementation of the DC-Flexhouse project. A prototype DC installation will be developed and tested in one of the buildings of the developing living lab area called the District of Tomorrow (De Wijk van Morgen which is located in Heerlen, the Netherlands. A neighborhood cooperative (Vrieheide cooperatie is also part of the consortium in order to address the aspect of social acceptance. Although DC seems to be a promising solution for a more sustainable energy system, the business case is still debatable due to both technology- and market-related challenges. The current energy infrastructure is predominantly based on AC, manufacturers produce devices based on AC standards and people are using many AC products across a long life span. This Smart Energy Buildings & Cities (SEB&C PDEng project is a contribution to the DC-Flexhouse project. The aim is to analyze the challenges in the transition to DC micro grids, assess the market potential of DC

  9. Properties of DLC coatings deposited by dc and dc with superimposed pulsed vacuum arc

    International Nuclear Information System (INIS)

    Zavaleyev, V.; Walkowicz, J.; Aksyonov, D.S.; Luchaninov, A.A.; Reshetnyak, E.N.; Strel'nitskij, V.E.

    2014-01-01

    Comparative studies of the structure, mechanical and tribological properties of DLC coatings deposited in DC and DC with superimposed high current pulse modes of operation vacuum-arc plasma source with the graphite cathode are presented. Imposition the pulses of high current on DC vacuum-arc discharge allows both increase the deposition rate of DLC coating and reduce the residual compressive stress in the coatings what promotes substantial improvement the adhesion to the substrate. Effect of vacuum arc plasma filtration with Venetian blind filter on the deposition rate and tribological characteristics of the coatings analyzed.

  10. Gambaran Status Gizi Anak Talasemia β Mayor di RSUP Dr. M. Djamil Padang

    Directory of Open Access Journals (Sweden)

    Dona Mirsa Putri

    2015-09-01

    Full Text Available Abstrak  Talasemia merupakan penyakit kronik yang membutuhkan transfusi setiap bulan, karena eritrosit lebih cepat lisis dibandingkan eritrosit normal. Komplikasi dan efek penyakit ini banyak, antara lain pertumbuhan, perkembangan, dan status gizinya. Penelitian ini bertujuan  mengetahui gambaran  status gizi anak talasemia β mayor Penelitian iniadalah penelitian deskriptif yang  dilakukan pada bulan Februari 2012 - Maret 2013 di RSUP Dr. M. Djamil Padang dengan sampel anak talasemia β mayor. Pemeriksaan yang dilakukan adalah mengukur tinggi badan, berat badan, dan lingkar lengan. Hasil pemeriksaan dimasukkan dalam tabel persentil NCHS dan penilaian status gizi berdasarkanDepartemen Kesehatan Repubik Indonesia.Hasil penelitian ini terdapat 15 anak talasemia β mayor, dengan rata-rata umur kelompok 5-10 tahun. Frekuensi terbanyak indeks tinggi badan per umur yaitu 70%-90% (60%.. Frekuensi terbanyak indeks berat badan per umur adalah 60%-80% (66.7%. Frekuensi terbanyak indeks lingkar lengang atas per umur adalah 70%-85% (80%. Simpulan dari hasil penelitian status gizi anak talasemia β mayor adalah gizi kurang.Kata kunci: Status gizi, talasemia β mayorAbstract Thalassemia is a chronic disease who needs blood tranfusion every month because the abnormal erythrocyte has short life time compared with the normal erythrocyte. There are so many complications and effects of this disease, such as growth and nutritional status. The aim of this research is to describe chlidren's nutritional status with thalassemia beta major. This research is a descriptive research. It has been done since February 2012 - March 2013 at RSUP Dr.  M. Djamil Padang. The sampling is children with thalassemia beta major. The examination are stature, weight, and upper arm circumference and the result is entered into NHCS percentil and assessment of Nutritional based on health department of Indonesia. From this research, there are 15 children who are suffering thalassemia

  11. Eficacia de la coronariografía en el adulto mayor

    Directory of Open Access Journals (Sweden)

    Luis Enrique Arozarena Díaz

    2015-06-01

    Full Text Available Introducción: se considera adulto mayor a toda persona cuya edad supere los 60 años, aunque se admite que este criterio no toma en cuenta: los procesos degenerativos, las alteraciones clínicas crónicas, la incapacidad y la dependencia. Objetivo: determinar la eficacia y seguridad de la coronariografía y el intervencionismo coronario percutáneo en el adulto mayor. Material y método: se realizó un estudio retrospectivo y descriptivo con los 5715 pacientes. A estos se les realizó una coronariografía en el laboratorio de hemodinámica del Cardiocentro procedente de Pinar del Río, entre 2010 y 2013. La muestra quedó formada por los 1933 mayores de 60 años. La información se obtuvo de la base de datos ANGYCOR, considerando las características clínico-angiográficas. Resultados: el diagnóstico más frecuente resultó la angina estable (43,5%. La edad promedio de 60 a 70 años, predominando el grupo de 60 a 69 años; la masculinidad (77,2% y la hipertensión arterial (64,9%. El 7,8% de los enfermos tenían una revascularización anterior. En el 98,0% el proceder resultó exitoso. Se concluyó que el índice de complicaciones y la mortalidad en coronariografía del adulto mayor es bajo, con elevado porcentaje de éxito, por lo que parece proceder eficaz y seguro. Conclusiones: el índice de realización de coronariografía a pacientes mayores de 60 años es bajo. La indicación del estudio, la presencia de enfermedad multivasos y del tronco de coronaria izquierda disminuyen a medida que aumenta la edad. La frecuencia de complicaciones, la mortalidad es nula con elevado índice de éxito.

  12. Hierarchical Control for Multiple DC-Microgrids Clusters

    DEFF Research Database (Denmark)

    Shafiee, Qobad; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2014-01-01

    DC microgrids (MGs) have gained research interest during the recent years because of many potential advantages as compared to the ac system. To ensure reliable operation of a low-voltage dc MG as well as its intelligent operation with the other DC MGs, a hierarchical control is proposed in this p......DC microgrids (MGs) have gained research interest during the recent years because of many potential advantages as compared to the ac system. To ensure reliable operation of a low-voltage dc MG as well as its intelligent operation with the other DC MGs, a hierarchical control is proposed...

  13. Modeling and simulation for micro DC motor based on simulink

    Science.gov (United States)

    Shen, Hanxin; Lei, Qiao; Chen, Wenxiang

    2017-09-01

    The micro DC motor has a large market demand but there is a lack of theoretical research for it. Through detailed analysis of the commutation process of micro DC motor commutator, based on micro DC motor electromagnetic torque equation and mechanical torque equation, with the help of Simulink toolkit, a triangle connection micro DC motor simulation model is established. By using the model, a sample micro DC motor are simulated, and an experimental measurements has been carried on the sample micro DC motor. It is found that the simulation results are consistent with theoretical analysis and experimental results.

  14. Power Quality in DC Power Distribution Systems and Microgrids

    Directory of Open Access Journals (Sweden)

    Stephen Whaite

    2015-05-01

    Full Text Available This review paper discusses power quality considerations for direct current (DC electric power distribution systems, particularly DC microgrids. First, four selected sample DC architectures are discussed to provide motivation for the consideration of power quality in DC systems. Second, a brief overview of power quality challenges in conventional alternating current (AC distribution systems is given to establish the field of power quality. Finally, a survey of literature addressing power quality issues in DC systems is presented, and necessary power quality considerations in DC distribution system design and operation are discussed.

  15. Halbach array DC motor/generator

    Science.gov (United States)

    Merritt, B.T.; Dreifuerst, G.R.; Post, R.F.

    1998-01-06

    A new configuration of DC motor/generator is based on a Halbach array of permanent magnets. This motor does not use ferrous materials so that the only losses are winding losses and losses due to bearings and windage. An ``inside-out`` design is used as compared to a conventional motor/generator design. The rotating portion, i.e., the rotor, is on the outside of the machine. The stationary portion, i.e., the stator, is formed by the inside of the machine. The rotor contains an array of permanent magnets that provide a uniform field. The windings of the motor are placed in or on the stator. The stator windings are then ``switched`` or ``commutated`` to provide a DC motor/generator much the same as in a conventional DC motor. The commutation can be performed by mechanical means using brushes or by electronic means using switching circuits. The invention is useful in electric vehicles and adjustable speed DC drives. 17 figs.

  16. Double-barrier junction based dc SQUID

    NARCIS (Netherlands)

    Bartolomé, M.E.; Brinkman, Alexander; Flokstra, Jakob; Golubov, Alexandre Avraamovitch; Rogalla, Horst

    2000-01-01

    dc SQUIDs based on double-barrier Nb/Al/AlOx/Al/AlOx/Al/Nb junctions (DBSQs) have been fabricated and tested for the first time. The current–voltage curves have been measured at temperatures down to 1.4 K. The critical current, Ic, dependence on the temperature T is partially described by the

  17. What should your DC default be?

    NARCIS (Netherlands)

    Cui, J.

    2009-01-01

    As reported, most DC pension scheme participants simply follow proposed defaults, even though they have the freedom to choose. Consequently, default designs have dramatic impacts on individuals’retirement saving outcomes. Given the fact that the default design matters, this paper evaluates

  18. Hierarchical Control for Multiple DC Microgrids Clusters

    DEFF Research Database (Denmark)

    Shafiee, Qobad; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2014-01-01

    This paper presents a distributed hierarchical control framework to ensure reliable operation of dc Microgrid (MG) clusters. In this hierarchy, primary control is used to regulate the common bus voltage inside each MG locally. An adaptive droop method is proposed for this level which determines...

  19. Voltage control of DC islanded microgrids

    DEFF Research Database (Denmark)

    Tucci, Michele; Riverso, Stefano; Quintero, Juan Carlos Vasquez

    2015-01-01

    We propose a new decentralized control scheme for DC Islanded microGrids (ImGs) composed by several Distributed Generation Units (DGUs) with a general interconnection topology. Each local controller regulates to a reference value the voltage of the Point of Common Coupling (PCC...

  20. Halbach array DC motor/generator

    Science.gov (United States)

    Merritt, Bernard T.; Dreifuerst, Gary R.; Post, Richard F.

    1998-01-01

    A new configuration of DC motor/generator is based on a Halbach array of permanent magnets. This motor does not use ferrous materials so that the only losses are winding losses and losses due to bearings and windage. An "inside-out" design is used as compared to a conventional motor/generator design. The rotating portion, i.e., the rotor, is on the outside of the machine. The stationary portion, i.e., the stator, is formed by the inside of the machine. The rotor contains an array of permanent magnets that provide a uniform field. The windings of the motor are placed in or on the stator. The stator windings are then "switched" or "commutated" to provide a DC motor/generator much the same as in a conventional DC motor. The commutation can be performed by mechanical means using brushes or by electronic means using switching circuits. The invention is useful in electric vehicles and adjustable speed DC drives.

  1. Gravity Compensation Technique Uses Small dc Motor

    Science.gov (United States)

    Hollow, Richard

    1988-01-01

    Small dc servomotor powered by simple constant-current source and with suitable gearing used to cancel effect of gravity upon load. Lead-screw positioning system has load counterbalanced by small supplementary motor powered by constant current source. Motor lighter and more compact alternative to counterbalance. Used in variety of mechanical systems where load positioned or accelerated in vertical plane.

  2. Computerized Torque Control for Large dc Motors

    Science.gov (United States)

    Willett, Richard M.; Carroll, Michael J.; Geiger, Ronald V.

    1987-01-01

    Speed and torque ranges in generator mode extended. System of shunt resistors, electronic switches, and pulse-width modulation controls torque exerted by large, three-phase, electronically commutated dc motor. Particularly useful for motor operating in generator mode because it extends operating range to low torque and high speed.

  3. Mayores Universitarios en la Red University Senior Students on the Web

    Directory of Open Access Journals (Sweden)

    Felicidad Loscertales Abril

    2011-10-01

    Full Text Available Hoy día la relevancia de Internet es cada vez mayor en todos los ámbitos. Participar en la misma es fundamental para estar integrados socialmente. El aumento de la esperanza y la calidad de vida conllevan que los mayores activos supongan un volumen significativo de la población. En este trabajo se analiza el uso que personas mayores activas realizan de Internet, así como los principales beneficios o motivaciones de su utilización, y las barreras que encuentran aquéllos que no la utilizan. Se administró un cuestionario a personas inscritas en programas universitarios de mayores. Los resultados muestran que estos mayores universitarios se conectan a Internet frecuentemente, a diario o entre dos o tres veces por semana. Se destaca la relevancia de Internet para estar actualizados, contactar con la familia y los amigos, el uso académico, y consultar la prensa. La consideran fácil de utilizar aunque afirman que podrían vivir sin ella. Por otro lado, para los que no acceden a Internet no saber utilizarla es una de las principales barreras, si bien las personas que no la utilizan consideran que serían capaces de aprender. En su conjunto los datos animan a romper estereotipos negativos sobre los mayores y a no considerar a los mayores activos como personas incapaces o desconectadas de la Red sino a valorar positivamente los avances que realizan y la motivación por aprender.The Internet is increasingly prominent in all walks of life, and Web connection is a key factor in social integration. The rise in life expectancy and quality of life mean that our active seniors now represent a growing sector in society. This study analyses what senior citizens use the Internet for and why, as well as the main benefits of its usage and the perceived obstacles of those who are non-users. The results derive from a questionnaire completed by senior citizens enrolled on university courses for older people, and they show that university seniors frequently

  4. DC photoemission electron guns as ERL sources

    International Nuclear Information System (INIS)

    Sinclair, Charles K.

    2006-01-01

    Very-high-voltage DC electron guns, delivering moderate duration bunches from photoemission cathodes, and followed by conventional drift bunching and acceleration, offer a practical solution for an ERL injector. In a variant of this scheme, a DC gun is placed in close proximity to a superconducting RF accelerator cavity, with few or no active elements between the gun and cavity. The principal technical challenge with such electron guns arises from field emission from the cathode electrode and its support structure. Field emission may result in voltage breakdown across the cathode-anode gap, or a punch-through failure of the insulator holding off the cathode potential, as well as lesser though still serious problems. Various means to mitigate these problems are described. The operational lifetime of high quantum efficiency photocathodes in these guns is determined by the vacuum conditions, through phenomena such as chemical poisoning and ion back-bombardment. Minimization of the field strength on electrode structures pushes high-voltage DC guns toward large dimensions and, correspondingly, large outgassing loads, but it is also true that these guns offer many opportunities for achieving excellent vacuum conditions. Good solutions to vacuum problems that had previously limited cathode lifetime have been demonstrated in recent years. Designs for DC guns presently in use and planned for the near future will be described. The parameters necessary for a 100 mA average current, very-high-voltage DC gun with a photocathode operational lifetime greater than 100 h appear to be within reach, but have yet to be demonstrated. A 1 A average current source with good cathode operational lifetime will require developments beyond the present state-of-the-art

  5. Homebuyer's Guide.

    Science.gov (United States)

    Sindt, Roger P.; Harris, Jack

    Designed to assist prospective buyers in making such important decisions as whether to buy a new or older home and within what price range, the guide provides information on the purchase process. Discussion of the purchase process covers the life-cycle costs (recurring homeownership costs that must be met every month); selection of a home;…

  6. ESTUDIOS BIOARQUEOLÓGICOS DEL SITIO PASO MAYOR, SUDOESTE DE LA PROVINCIA DE BUENOS AIRES / Bioarchaeological studies of Paso Mayor site, southwest Buenos Aires province

    Directory of Open Access Journals (Sweden)

    Clara Scabuzzo

    2013-07-01

    Full Text Available En este trabajo se resumen los estudios bioarqueológicos realizados en la colección osteológica del sitio Paso Mayor Y1S2 (partido de Coronel Pringles, Buenos Aires. Los análisis efectuados comprendieron diferentes etapas. En primer lugar se hizo un inventario de la colección y se relevaron algunas variables tafonómicas para conocer el estado general de conservación de los restos. Una segunda etapa estuvo orientada a determinar la estructura sexo-etaria de la muestra. Finalmente se efectuaron estudios de marcadores de estrés ocupacional y el relevamiento de algunas patologías de carácter infeccioso y traumático. En conjunto estos análisis muestran que en el sitio se inhumaron individuos subadultos y adultos de ambos sexos, los restos fueron enterrados de manera primaria y secundaria. La colección muestra un buen estado de conservación por lo que fue posible determinar la mayoría de los elementos óseos analizados. En cuanto a los estudios de marcadores de actividad física, estos indican la importancia de la actividad deambulatoria y el posible uso de sistemas de armas como el arco y flecha. Se registró una reacción perióstica en los miembros inferiores y un traumatismo en el esqueleto craneal. Finalmente se discute la información bioarqueológica del sitio con la publicada para otros sitios del área. Abstract This paper summarizes the bioarchaeological studies of the osteological collection recovered in Paso Mayor Y1S2 site (Coronel Pringles, Buenos Aires. Analyses were carried out in different stages. First, a detailed inventory of the collection was made and some taphonomic variables were considered in order to evaluate the general condition of the bone remains. A second phase was oriented to the determination of the age-sex structure of the sample. Finally, occupational stress markers studies were undertaken along with the observation of certain infectious and traumatic pathologies. As a whole, these analyses show the

  7. Current Mode Control for LLC Series Resonant DC-to-DC Converters

    Directory of Open Access Journals (Sweden)

    Jinhaeng Jang

    2015-06-01

    Full Text Available Conventional voltage mode control only offers limited performance for LLC series resonant DC-to-DC converters experiencing wide variations in operational conditions. When the existing voltage mode control is employed, the closed-loop performance of the converter is directly affected by unavoidable changes in power stage dynamics. Thus, a specific control design optimized at one particular operating point could become unacceptable when the operational condition is varied. This paper presents a new current mode control scheme which could consistently provide good closed-loop performance for LLC resonant converters for the entire operational range. The proposed control scheme employs an additional feedback from the current of the resonant tank network to overcome the limitation of the existing voltage mode control. The superiority of the proposed current mode control over the conventional voltage mode control is verified using an experimental 150 W LLC series resonant DC-to-DC converter.

  8. DC-DC power converter research for Orbiter/Station power exchange

    Science.gov (United States)

    Ehsani, M.

    1993-01-01

    This project was to produce innovative DC-DC power converter concepts which are appropriate for the power exchange between the Orbiter and the Space Station Freedom (SSF). The new converters must interface three regulated power buses on SSF, which are at different voltages, with three fuel cell power buses on the Orbiter which can be at different voltages and should be tracked independently. Power exchange is to be bi-directional between the SSF and the Orbiter. The new converters must satisfy the above operational requirements with better weight, volume, efficiency, and reliability than is available from the present conventional technology. Two families of zero current DC-DC converters were developed and successfully adapted to this application. Most of the converters developed are new and are presented.

  9. Differential Mode EMI Filter Design for Isolated DC-DC Boost Converter

    DEFF Research Database (Denmark)

    Makda, Ishtiyaq Ahmed; Nymand, Morten

    2014-01-01

    A Differential Mode EMI filter for a low input voltage high-current isolated dc-dc boost converter is designed and presented in this paper. The primary side Differential Mode noise voltage is low due to the high transformer turn ratio, however, the input current is very high and since the EMI limit...... also does not change for such converters, it requires greatly optimized design approach for the filter including the correct sizing of the filter components. A complete analytical filter design process is carried out such a way that the Differential Mode noise voltage source in the converter...... is identified first. The DM noise model is then established and based on the harmonic analysis of the noise source voltage waveform, the complete Differential Mode EMI filter, including the filter resonance damping branch, is designed for a 3kW isolated dc-dc boost converter. The noise model and its theoretical...

  10. Multi-level cascaded DC/DC converters for PV applications

    Directory of Open Access Journals (Sweden)

    Ahmed A.A. Hafez

    2015-12-01

    Full Text Available A robust multi-level cascaded DC/DC system for Photovoltaic (PV application is advised in this article. There are three PV generators, each is coupled to a half-bridge buck cell. Each PV-generator–buck-converter channel is controlled such that maximum power is captured independently under different irradiation and temperature levels. The system operation under normal and abnormal conditions was comprehensively investigated. Internal Model Control (IMC technique was adopted for tuning the controllers. An elaborate switching modulation strategy was used to reduce the current ripple and inductor size, while maintaining high efficiency. Annotative, simple and robust remedial strategies were proposed to mitigate different anticipated faults. Comprehensive simulation results in Matlab environment were illustrated for corroborating the performance of the advised cascaded DC/DC system under normal/abnormal conditions. The proposed system enjoys the merits of independency, reduced volumetric dimensions and improved efficiency. Furthermore, the system is inherently fault-tolerant.

  11. High Voltage Coil Current Sensor for DC-DC Converters Employing DDCC

    Directory of Open Access Journals (Sweden)

    M. Drinovsky

    2015-12-01

    Full Text Available Current sensor is an integral part of every switching converter. It is used for over-current protection, regulation and in case of multiphase converters for balancing. A new high voltage current sensor for coil-based current sensing in DC-DC converters is presented. The sensor employs DDCC with high voltage input stage and gain trimming. The circuit has been simulated and implemented in 0.35 um BCD technology as part of a multiphase DC-DC converter where its function has been verified. The circuit is able to sustain common mode voltage on the input up to 40 V, it occupies 0.387*0.345 mm2 and consumes 3.2 mW typically.

  12. Analysis of the Coupling Behavior of PEM Fuel Cells and DC-DC Converters

    Directory of Open Access Journals (Sweden)

    Achim Kienle

    2009-03-01

    Full Text Available The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neither stationary multiplicities nor oscillations can be introduced by the couplings and therefore separate control approaches for both the PEMFC and the DC-DC converters are applicable.

  13. Integrated Three-Port DC-DC Converter for Photovoltaic (PV) Battery Stand-alone Systems

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2016-01-01

    of solar energy. Moreover, a novel transformer configuration enables variable turns ratio controlled by the phase between the two current excitations subjected to the primary windings, allowing a wider input/output range. 1 kW experimental prototype has been built to demonstrate a wellmanaged power flow......Several power sources such as PV solar arrays and battery are often used to manage the power flow for a photovoltaic (PV) based stand-alone power system due to the fluctuation nature of solar energy resource, and deliver a continuous power to the users in an appropriate form. Traditionally, three...... different single-input single-output (SISO) dc/dc converters would have been used. To reduce the cost and improve the power density of the system, an integrated three-port isolated dc/dc converter is proposed in this paper. It can realize all functions of the energy delivery due to the fluctuation nature...

  14. single-phase dc phase dc-ac boost converter ac boost converter

    African Journals Online (AJOL)

    User

    systems, need to step-up the DC input voltage. increase the ... design also makes for extra parts, greater system and weight, [1-3]. ... proposes a new design for high performance sin ... SYSTEM ANALYSIS. 2. ..... from the simulation study.

  15. Y-source impedance-network-based isolated boost DC/DC converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Town, Graham; Loh, Poh Chiang

    2014-01-01

    A dc-dc converter with very high voltage gain is proposed in this paper for any medium-power application requiring a high voltage boost with galvanic isolation. The proposed converter topology can be realized using only two switches. With this topology a very high voltage boost can be achieved even...... with a relatively low duty cycle of the switches, and the gain obtainable is presently not matched by any existing impedance network based converter operated at the same duty ratio. The proposed converter has a Y-source impedance network to boost the voltage at the intermediate dc-link side and a push......-pull transformer for square-wave AC inversion and isolation. The voltage-doubler rectifier provides a constant dc voltage at the output stage. A theoretical analysis of the converter is presented, supported by simulation and experimental results. A 250 W down-scaled prototype was implemented in the laboratory...

  16. SUBCONTRACT REPORT: DC-DC Converter for Fuel Cell and Hybrid Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Marlino, Laura D [ORNL; Zhu, Lizhi [Ballard Power Systems/Siemens VDO

    2007-07-01

    The goal of this project is to develop and fabricate a 5kW dc-dc converter with a baseline 14V output capability for fuel cell and hybrid vehicles. The major objectives for this dc-dc converter technology are to meet: Higher efficiency (92%); High coolant temperature,e capability (105 C); High reliability (15 Years/150,000miles); Smaller volume (5L); Lower weight (6kg); and Lower cost ($75/kW). The key technical challenge for these converters is the 105 C coolant temperatures. The power switches and magnetics must be designed to sustain these operating temperatures reliably, without a large cost/mass/volume penalty.

  17. Washington DC Metropolitan Area Drug Study Household and Non-Household Populations (DC-MADSH-1991)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The DC Metropolitan Area Drug Study (DCMADS) was conducted in 1991, and included special analyses of homeless and transient populations and of women delivering live...

  18. Circuit description of unipolar DC-to-DC converters for APS storage ring quadrupoles and sextupoles

    International Nuclear Information System (INIS)

    McGhee, D.G.

    1993-01-01

    This paper describes the control, interlock, and power circuits for 680 unipolar switch mode DC-to-DC converters used to regulate the Advanced Photon Sources (APS's) storage ring quadrupole and sextupole magnet currents. Quadrupole current stability is ± 6x10 -5 and the sextupole current stability is ±3x10 -4 . The stability is obtained with pulse width modulation, operating at a switching frequency of 20kHz with full current switching. The converters are housed in 200 cabinets located on top of the storage ring tunnel. Raw DC power is distributed from 80 AC-to-DC power supplies, four at each of 20 locations around the storage ring. Voltages, currents, and temperatures are computer monitored and logged for the converters and magnets. All converters and magnets are water cooled with the flow and pressure monitored at the inlet and outlet of groups. Water is interlocked with the raw power supplies and not the individual converters

  19. Research of digital controlled DC/DC converter based on STC12C5410AD

    Science.gov (United States)

    Chen, Dan-Jiang; Jin, Xin; Xiao, Zhi-Hong

    2010-02-01

    In order to study application of digital control technology on DC/DC converter, principle of increment mode PID control algorithm was analyzed in the paper. Then, a SCM named STC12C5410AD was introduced with its internal resources and characteristics. The PID control algorithm can be implemented easily based on it. The output of PID control was used to change the value of a variable that is 255 times than duty cycle, and this reduced the error of calculation. The valid of the presented algorithm was verified by an experiment for a BUCK DC/DC converter. The experimental results indicated that output voltage of the BUCK converter is stable with low ripple.

  20. Washington DC Metropolitan Area Drug Study Homeless and Transient Population (DC-MADST-1991)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The DC Metropolitan Area Drug Study (DCMADS) was conducted in 1991, and included special analyses of homeless and transient populations and of women delivering live...

  1. Improvement of burst-mode control of piezoelectric transformer based DC/DC converter

    International Nuclear Information System (INIS)

    Vasic, Dejan; Liu, Yuan-Ping; Costa, François; Schwander, Denis; Wu, Wen-Jong

    2013-01-01

    Burst-mode operation is adopted sometimes in piezoelectric transformer based converters for two major purposes: (1) to achieve voltage regulation in DC/DC converters and (2) to achieve dimming control in backlight inverters. Burst-mode control enables the converter to operate at a constant switching frequency as well as to maintain good efficiency at light load conditions. However, in practice, the piezoelectric transformer cannot instantly stop vibrating in the burst-mode due to its high quality factor. The delay in the output voltage change resulting from this behavior influences the accuracy of the regulation. This paper proposes a control strategy to make the piezoelectric transformer stop more quickly so as to enhance the accuracy of burst-mode control. The proposed method only modifies the control signal of the burst-mode driving circuit. The proposed control strategy is verified by experiments in a step-down 9 W DC/DC converter. (paper)

  2. Current Mode Control for LLC Series Resonant DC-to-DC Converters

    OpenAIRE

    Jinhaeng Jang; Syam Kumar Pidaparthy; Byungcho Choi

    2015-01-01

    Conventional voltage mode control only offers limited performance for LLC series resonant DC-to-DC converters experiencing wide variations in operational conditions. When the existing voltage mode control is employed, the closed-loop performance of the converter is directly affected by unavoidable changes in power stage dynamics. Thus, a specific control design optimized at one particular operating point could become unacceptable when the operational condition is varied. This paper presents a...

  3. LPV model for PV cell and fractional control of DC/DC converter for photovoltaic systems

    OpenAIRE

    Martínez González, Rubén; Bolea Monte, Yolanda; Grau Saldes, Antoni; Martínez García, Herminio

    2011-01-01

    This paper deals with the fractional modelling of a DC-DC converter, suitable in solar-powered electrical generation systems, and the design of a fractional controller for the aforementioned switching converter. A new model for PV cells is proposed in order to obtain a linear equation for V-I characteristic via scheduling dependence of temperature and irradiance. Due to the fractional nature of the ultracapacitors this kind of controller gives a suitable and good performance. Peer Reviewed

  4. LPV model for PV cells and fractional control of DC/DC converter for photovoltaic systems

    OpenAIRE

    Martínez González, Rubén; Bolea Monte, Yolanda; Grau Saldes, Antoni; Martínez García, Herminio

    2011-01-01

    This paper deals with the fractional modelling of a DC-DC converter, suitable in solar-powered electrical generation systems, and the design of a fractional controller for the aforementioned switching converter. A new model for PV cells is proposed in order to obtain a linear equation for VI characteristic via scheduling dependence of temperature and irradiance. Due to the fractional nature of the ultracapacitors this kind of controller gives a suitable and good performance. Peer Rev...

  5. Distributed maximum power point tracking in photovoltaic applications: active bypass DC/DC converter

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2012-01-01

    Full Text Available Se propone una estructura de desvío activo para maximizar la producción de potencia en sistemas fotovoltaicos bajo condiciones irregulares de operación, comparando su eficiencia con soluciones individuales y distribuidas basadas en convertidores DC/DC convencionales. Los análisis y simulaciones realistas demuestran las ventajas del nuevo convertidor de desvío activo sobre soluciones basadas en convertidores Boost, Buck y Buck-Boost.

  6. Analisa Perbandingan Efisiensi Motor Dc Kompon Pendek Dengan Motor Dc Kompon Panjang Akibat Penambahan Kutub

    OpenAIRE

    Sitompul, Fuad Rahim

    2015-01-01

    Motor listrik merupakan perangkat elekromagnetis yang mengubah energi listrik menjadi energi mekanik. Motor DC memerlukan tegangan searah pada kumparan medan untuk diubah menjadi energi mekanik. Energi mekanik ini digunakan sebagai penggerak peralatan listrik seperti pompa,penggerak kipas angin, lift dan lain-lain. Karena penggunaannya yang cukup luas maka kinerjanya harus baik. Kinerja suatu motor DC dikatakan baik jika efisiensi motor tersebut tinggi. Hal itu dapat dicapai dengan mengatur b...

  7. Soft switching bidirectional DC-DC converter for ultracapacitor-batteries interface

    International Nuclear Information System (INIS)

    Adib, Ehsan; Farzanehfard, Hosein

    2009-01-01

    In this paper a new soft switching bidirectional DC-DC converter is introduced which can be applied as the interface circuit between ultracapacitors and batteries or fuel cells. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. Due to achieved soft switching condition, the energy conversion through the proposed converter is highly efficient. The proposed converter is analyzed and a prototype converter is implemented. The presented experimental results confirm the theoretical analysis.

  8. Soft switching bidirectional DC-DC converter for ultracapacitor-batteries interface

    Energy Technology Data Exchange (ETDEWEB)

    Adib, Ehsan; Farzanehfard, Hosein [Dept. of Electrical and Computer Engineering, Isfahan Univ. of Technology (Iran)

    2009-12-15

    In this paper a new soft switching bidirectional DC-DC converter is introduced which can be applied as the interface circuit between ultracapacitors and batteries or fuel cells. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. Due to achieved soft switching condition, the energy conversion through the proposed converter is highly efficient. The proposed converter is analyzed and a prototype converter is implemented. The presented experimental results confirm the theoretical analysis. (author)

  9. Comparative efficiency evaluation of buck and hybrid buck DC-DC converters for automotive applications

    DEFF Research Database (Denmark)

    Pelan, Ovidiu; Cornea, Octavian; Muntean, Nicolae

    2014-01-01

    This paper presents and discusses design considerations and efficiency investigation of a conventional step-down and a hybrid switched-capacitor DC-DC converter. Three MOSFETs with low on-resistance have been tested for each converter in order to find the most adequate switch for this application....... The experimental results and comparative efficiency graphs were obtained with a 1kW laboratory prototype dedicated for a 42/14V dual voltage automotive system....

  10. Simulating and Testing a DC-DC Half-Bridge SLR Converter

    Science.gov (United States)

    2013-06-01

    future pulse power demands with ship power, a large bank of capacitors or similar rapid discharge source is required. If capacitors are charged...Single Pulsed Avalanche Energy (j) I" Avalanche Current (i) E,, Repetilive Avalanche Energy (i) dv/dt Peak Diode Recovery dv/dt ® Po Total Power...SLR), battery charging, DC-DC, pulse power, power electronics, SLR converter 15. NUMBER OF PAGES 119 16. PRICE CODE 17. SECURITY CLASSIFICATION

  11. Sliding-mode control of single input multiple output DC-DC converter

    Science.gov (United States)

    Zhang, Libo; Sun, Yihan; Luo, Tiejian; Wan, Qiyang

    2016-10-01

    Various voltage levels are required in the vehicle mounted power system. A conventional solution is to utilize an independent multiple output DC-DC converter whose cost is high and control scheme is complicated. In this paper, we design a novel SIMO DC-DC converter with sliding mode controller. The proposed converter can boost the voltage of a low-voltage input power source to a controllable high-voltage DC bus and middle-voltage output terminals, which endow the converter with characteristics of simple structure, low cost, and convenient control. In addition, the sliding mode control (SMC) technique applied in our converter can enhance the performances of a certain SIMO DC-DC converter topology. The high-voltage DC bus can be regarded as the main power source to the high-voltage facility of the vehicle mounted power system, and the middle-voltage output terminals can supply power to the low-voltage equipment on an automobile. In the respect of control algorithm, it is the first time to propose the SMC-PID (Proportion Integration Differentiation) control algorithm, in which the SMC algorithm is utilized and the PID control is attended to the conventional SMC algorithm. The PID control increases the dynamic ability of the SMC algorithm by establishing the corresponding SMC surface and introducing the attached integral of voltage error, which endow the sliding-control system with excellent dynamic performance. At last, we established the MATLAB/SIMULINK simulation model, tested performance of the system, and built the hardware prototype based on Digital Signal Processor (DSP). Results show that the sliding mode control is able to track a required trajectory, which has robustness against the uncertainties and disturbances.

  12. Informational model verification of ZVS Buck quasi-resonant DC-DC converter

    Science.gov (United States)

    Vakovsky, Dimiter; Hinov, Nikolay

    2016-12-01

    The aim of the paper is to create a polymorphic informational model of a ZVS Buck quasi-resonant DC-DC converter for the modeling purposes of the object. For the creation of the model is applied flexible open standards for setting, storing, publishing and exchange of data in distributed information environment. The created model is useful for creation of many and different by type variants with different configuration of the composing elements and different inner model of the examined object.

  13. ITAR Free Commercial-of-the-Shelf DC/DC Converter

    Science.gov (United States)

    Denzinger, Wolfgang; Hintze, Thomas

    2014-08-01

    A commercial-of-the-shelf (COTS) DC/DC converter for digital space equipment has been developed by ASP under ESA contract with special emphasis on low cost, no use of ITAR listed EEE parts like Mosfets, minimum number of rad-hard digital IC's and a design tolerance against single event effects by appropriate filtering. However, the intention to qualify this discrete converter design for a low cost FM series production was difficult due to the high up-sceening cost of EEE-parts with one lot guarantee and minimum-by. To overcome this problem, in a next step a redesign of the DC/DC converter was performed with all semiconductors like bipolar transistors, rectifiers and zener diodes packaged into hybrids. With this approach it was possible to buy a high number of less expensive wafers or dies from one lot, to perform a lot acceptance test and to integrate the dies into hybrid packages with further up- screening for FM use. The semiconductors have been packaged into three signal hybrids with 44 pins and one power hybrid with 24 pins for the dissipating transistors and rectifiers. The design of the hybrids is such, that all integrated semiconductors can be tested individually. The qualification of four EQM DC/DC converters with different combinations of output voltages has been successfully performed and two FM's have been manufactured and tested.

  14. Design and implementation of current fed DC-DC converter for PHEV application using renewable source

    Science.gov (United States)

    Milind Metha, Manish; Tutki, Sanjay; Rajan, Aju; Elangovan, D.; Arunkumar, G.

    2017-11-01

    As the fossil fuels are depleting day by day, the use of renewable energy sources came into existence and they evolved a lot lately. To increase efficiency and productivity in the hybrid vehicles, the existence less efficient petroleum and diesel IC engines need to be replaced with the new and efficient converters with renewable energy sources. This has to be done in such a way that impacts three factors mainly: cost, efficiency and reliability. The PHEVs that have been launched and the upcoming PHEVs using converters with voltage range around 380V to 400V generated with power ranges between 2.4KW to 2.8KW. The basic motto of this paper is to design a prolific converter while considering the factor such as cost and size. In this paper, a two stage DC-DC converter is proposed and the proposed DC-DC converter is utilized to endeavour voltage from 24V (photovoltaic source) to a yield voltage of 400V and to meet the power demand of 250W, since only one panel is being used for this proposed paper. This paper discuss in detail about why and how the current fed DC-DC converter is utilized along with a voltage doubler, thus reducing transformer turns and thereby reducing overall size of the product. Simulation and hardware results have been presented along with calculations for duty cycle required for firing sequence for different values of transformer turns.

  15. CAMEX-4 DC-8 DROPSONDE SYSTEM V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-4 DC-8 Dropsonde System dataset was collected by the DC-8 Dropsonde System (D8D) uses dropwindsonde and Global Positioning System (GPS) receivers to...

  16. control of a dc motor using fuzzy logic control algorithm

    African Journals Online (AJOL)

    user

    controller in the control performance of an industrial type DC motor using MATLAB. The fuzzy logic .... controlled separately excited permanent magnet DC motor (PMDC). ... When the field current is constant, the flux induced by the field ...

  17. Brushless dc motor uses electron beam switching tube as commutator

    Science.gov (United States)

    Studer, P.

    1965-01-01

    Electron beam switching tube eliminates physical contact between rotor and stator in brushless dc motor. The tube and associated circuitry control the output of a dc source to sequentially energize the motor stator windings.

  18. Trends and determinants of cycling in the Washington, DC region.

    Science.gov (United States)

    2011-01-01

    This report analyzes cycling trends, policies, and commuting in the Washington, DC area. The analysis is divided into two parts. : Part 1 focuses on cycling trends and policies in Washington (DC), Alexandria (VA), Arlington County (VA), Fairfax Count...

  19. Peso corporal y depresión en adultos mayores de comunidad urbano marginal en México - Tamaulipas.

    OpenAIRE

    Duran-Badillo, Tirso; Martínez Aguilar, Ma. de la Luz; Gutiérrez Sánchez, Gustavo; Rosa Ma., Rosa Ma.; Guevara-Valtie, Milton Carlos

    2016-01-01

    El peso corporal inadecuado y la depresión son factores que alteran la calidad de vida del adulto mayor. Objetivos: identificar asociación existente entre peso corporal y depresión en el adulto mayor. Material y Metodos: estudio descriptivo y correlacional, se realizó en una población urbano-marginal de Tamaulipas, México. Participaron 252 adultos mayores de 60 años y que tuvieran la capacidad física para mantenerse de pié al momento de medir el peso corporal y talla. El muestreo fue no proba...

  20. Maltrato intrafamiliar hacia el adulto mayor en el del Policlínico Reynold García de Versalles

    OpenAIRE

    García Rosique, Regla Mercedes; Guisado Zamora, Katia; Torres Triana, Adelaida

    2016-01-01

    Introducción: el maltrato al adulto mayor emerge como problema social, desde hace pocos años, y no porque antes no existiera, sino porque muchas veces existe en las familias y no sale a la luz pública. Objetivo: identificar maltrato intrafamiliar hacia los adultos mayores. Materiales y Métodos: se realizó un estudio descriptivo, de corte transversal en 60 adultos mayores de 60 años, pertenecientes al Consultorio Médico de Familia No. 87, del Policlínico Reynold García, área de Versalles de la...

  1. Los Centros y espacios de actividad física utilizados por las personas mayores en España

    OpenAIRE

    Jiménez-Beatty Navarro, Jose Emilio; Martínez del Castillo, Jesus; Hierro Pinés, David del; Martin Rodriguez, Maria; González Rivera, Maria Dolores

    2008-01-01

    El objeto de la comunicación ha consistido en abordar las instalaciones y espacios utilizados por las personas mayores que realizan actividad física semanalmente. El método ha consistido en la realización de una encuesta, en la que mediante entrevista personal se ha aplicado un cuestionario a una muestra aleatoria de la población de personas mayores en España. Los resultados muestran que la mayor parte de estas personas practican en espacios cubiertos y de instalaciones deportivas (sobre todo...

  2. Design of an Input-Parallel Output-Parallel LLC Resonant DC-DC Converter System for DC Microgrids

    Science.gov (United States)

    Juan, Y. L.; Chen, T. R.; Chang, H. M.; Wei, S. E.

    2017-11-01

    Compared with the centralized power system, the distributed modularized power system is composed of several power modules with lower power capacity to provide a totally enough power capacity for the load demand. Therefore, the current stress of the power components in each module can then be reduced, and the flexibility of system setup is also enhanced. However, the parallel-connected power modules in the conventional system are usually controlled to equally share the power flow which would result in lower efficiency in low loading condition. In this study, a modular power conversion system for DC micro grid is developed with 48 V dc low voltage input and 380 V dc high voltage output. However, in the developed system control strategy, the numbers of power modules enabled to share the power flow is decided according to the output power at lower load demand. Finally, three 350 W power modules are constructed and parallel-connected to setup a modular power conversion system. From the experimental results, compared with the conventional system, the efficiency of the developed power system in the light loading condition is greatly improved. The modularized design of the power system can also decrease the power loss ratio to the system capacity.

  3. DC-DC Type High-Frequency Link DC for Improved Power Quality of Cascaded Multilevel Inverter

    Science.gov (United States)

    Sadikin, Muhammad; Senjyu, Tomonobu; Yona, Atsushi

    2013-06-01

    Multilevel inverters are emerging as a new breed of power converter options for power system applications. Recent advances in power switching devices enabled the suitability of multilevel inverters for high voltage and high power applications because they are connecting several devices in series without the need of component matching. Usually, a transformerless battery energy storage system, based on a cascaded multilevel inverter, is used as a measure for voltage and frequency deviations. System can be reduced in size, weight, and cost of energy storage system. High-frequency link circuit topology is advantageous in realizing compact and light-weight power converters for uninterruptible power supply systems, new energy systems using photovoltaic-cells, fuel-cells and so on. This paper presents a DC-DC type high-frequency link DC (HFLDC) cascaded multilevel inverter. Each converter cell is implemented a control strategy for two H-bridge inverters that are controlled with the same multicarrier pulse width modulation (PWM) technique. The proposed cascaded multilevel inverter generates lower voltage total harmonic distortion (THD) in comparison with conventional cascaded multilevel inverter. Digital simulations are carried out using PSCAD/EMTDC to validate the performance of the proposed cascaded multilevel inverter.

  4. Usos y gratificaciones de los ordenadores en personas mayores en Sudáfrica

    Directory of Open Access Journals (Sweden)

    Tanja Bosch

    2015-07-01

    Full Text Available A partir de entrevistas en profundidad, realizadas en un hogar de la tercera edad en Ciudad del Cabo (Sudáfrica, este estudio analiza los principales usos y gratificaciones que reciben las personas mayores en interacción con los ordenadores. En África, mientras el énfasis investigador se ha puesto en los últimos años en la salud de los mayores, especialmente en cuanto al SIDA, existe muy poca investigación sobre el uso de los mayores en cuanto a nuevas tecnologías, ya que la investigación en relación con las mismas se ha centrado principalmente en la juventud. En este estudio se halló que los participantes utilizan el correo electrónico y las redes sociales para mantener el contacto con familiares y amigos y a veces incluso con su vecindario. Además, mantener el contacto suponía no solo comunicación, sino también observación de actividades, como noticias, fotografías y conversaciones. En el contexto de los usos y gratificaciones, el trabajo ha evidenciado que los participantes se sentían conectados con la sociedad, tanto por su comunicación como por la observación de las personas, y por mantenerse informados de las noticias y los temas de interés actuales. Mediante el uso de Internet, las personas de edad avanzada se comunicaban mucho más de lo que antes se habían comunicado con otras personas. Algunos de los participantes se sentían menos aislados y solos, debido a su uso del ordenador. Sin embargo, se demostró también que el uso de los ordenadores no obstaculizó los contactos interpersonales tradicionales.

  5. Diferencias relacionadas con la salud de mujeres y hombres adultos mayores

    Directory of Open Access Journals (Sweden)

    Ileana E Castañeda Abascal

    Full Text Available Introducción: la humanidad se enfrenta a la elevación del número de ancianos(as. Cuba no es una excepción. La salud en ancianos(as es diferente, debido a los factores biológicos, psicológicos y culturales a que están expuestos a lo largo de la vida, de ahí la necesidad de su estudio. Objetivos: identificar las diferencias relacionadas con la salud de mujeres y hombres adultos mayores en el área de salud Cuatro Caminos, durante el año 2009. Métodos: se realizó una investigación descriptiva y transversal. El universo estuvo constituido por los 1 562 ancianos (761 mujeres y 801 hombres residentes en el área de salud Cuatro Caminos. La información se recolectó a través de los registros de adultos mayores, hojas de cargo de los consultorios médicos de la familia, y una entrevista semiestructurada aplicada a la totalidad del universo. Resultados: las edades más representadas para ambos sexos estuvieron entre 60 y 79 años. Tanto mujeres como hombres padecían enfermedades crónicas, destacándose la hipertensión arterial. Las féminas fueron más frecuentes en los ancianos frágiles y en estado de necesidad. Los ancianos solos fueron mayoritariamente hombres. Las mujeres se realizaron más los exámenes periódicos de salud y recibieron atención domiciliaria. Conclusiones: la salud, las actividades que realizan y la atención geriátrica son diferentes en mujeres y hombres adultos mayores.

  6. Calidad de vida en adultos mayores del hogar de ancianos del municipio Cruces

    Directory of Open Access Journals (Sweden)

    María del Carmen Corugedo Rodríguez

    Full Text Available Introducción: el proceso de envejecimiento es un hecho relevante para todos los sistemas de salud en el mundo debido a la transición demográfica. Cuba no está exenta de esta realidad, por lo que la calidad de vida del adulto mayor es un tema de gran importancia. Objetivo: caracterizar la calidad de vida percibida en los adultos mayores del Hogar de Ancianos del municipio Cruces. Métodos: se realizó un estudio observacional descriptivo de corte transversal durante el periodo de febrero de 2012 a febrero de 2013. El universo estuvo constituido por los 28 ancianos que viven en el hogar de ancianos del municipio Cruces. La información se obtuvo con la aplicación de la Escala M.G.H. Se aplicaron técnicas estadísticas. Resultados: de forma general los ancianos perciben baja calidad de vida, independientemente de las variables sociodemográficas (edad, sexo y nivel de escolaridad. La dimensión de resultados más bajos fue la satisfacción por la vida. El 82 % de los adultos mayores perciben una baja calidad de vida en relación con la misma, seguida por la dimensión socioeconómica. Conclusiones: casi todos los ancianos de la investigación perciben una baja calidad de vida, debido al predominio de estados de displacer y pobres vínculos o mala calidad en las relaciones con sus familiares.

  7. Índice de vulnerabilidad de adultos mayores en Medellín, Barranquilla y Pasto.

    Science.gov (United States)

    Cardona, Doris; Segura, Ángela; Segura, Alejandra; Muñoz, Diana; Jaramillo, Daniel; Lizcano, Douglas; Agudelo, Maite Catalina; Arango, Catalina; Morales, Santiago

    2018-05-01

    Introducción. La vulnerabilidad puede entenderse como la carencia de recursos materiales e inmateriales que impide el aprovechamiento de oportunidades en distintos aspectos de la vida. Estos recursos de bienestar evitan el deterioro de la calidad de vida.Objetivo. Construir un índice de vulnerabilidad con las características de los capitales físico, humano, social y funcional de los adultos mayores de tres ciudades de Colombia en el 2016, y determinar los factores asociados con esta condición.Materiales y métodos. Se hizo un estudio transversal con información primaria mediante 1.514 encuestas a personas de 60 años o más de Medellín, Barranquilla y Pasto. En la construcción del índice se usó el análisis factorial con los métodos de componentes principales y de rotación ortogonal varimax.Resultados. Las condiciones que generaban vulnerabilidad se relacionaron principalmente con el capital humano (calidad de vida, salud mental y hábitos); los demás capitales aportaron un solo componente, así: capital físico (ocupación), capital social (acompañamiento) y capital funcional (independencia funcional). La vulnerabilidad fue mayor en los residentes de Pasto. Los factores asociados con la vulnerabilidad fueron la ciudad de residencia, el sexo, el nivel educativo y el rol en el hogar.Conclusión. En el 58,55 % de las personas mayores, la vulnerabilidad se explicó por el uso del tiempo, la independencia funcional y el bienestar subjetivo. Estos hallazgos aportan elementos para el mejoramiento de la calidad de vida, principalmente en cuanto a la capacidad funcional para mantener la independencia, estar ocupados y fortalecer la salud mental.

  8. Efecto de dos protocolos de ejercicios en personas mayores de 65 años institucionalizadas

    Directory of Open Access Journals (Sweden)

    Yolanda Marcen Román

    2014-12-01

    Full Text Available Entre la población mayor, uno de los pilares centrales de la calidad de vida es la salud, adquiriendo especial importancia la condición física como capacidad para mantener la independencia funcional. El objetivo general es medir el efecto sobre el equilibrio estático y dinámico, la fuerza y la flexibilidad de ambas extremidades tras un periodo de 3 meses de intervención y posteriormente las consecuencias de otros tres meses sin ejercicios.Metodología: Estudio pre-post intervención en una muestra de 36 ancianos institucionalizados mayores de 65 años con deterioro cognitivo normal-leve, divididos en 3 grupos: ejercicios vestibulares, ejercicios de potenciación y grupo control sin intervención. Resultados: Mejoría significativa del equilibrio, la flexibilidad y la fuerza muscular de miembros inferiores en cada uno de los grupos de intervención con respecto al grupo control. Disminución de la capacidad funcional medida a través de una batería de test tras 3 meses sin intervención. Conclusiones: El equilibrio, la fuerza y la flexibilidad de extremidades inferiores y superiores en personas mayores de 65 años institucionalizadas del presente estudio mejoran con la realización de los protocolos de tratamiento diseñados a partir de ejercicios de potenciación de miembros inferiores y de ejercicios vestibulares, en relación al grupo control. La capacidad funcional va disminuyendo si no se realizan de forma continua ejercicios encaminados a fomentarla

  9. Envejecimiento satisfactorio e indicadores de fragilidad en los mayores de la comunidad. Estudio Octabaix

    OpenAIRE

    Ferrer, Assumpta; Formiga, Francesc; Sanz, Héctor; Monserrate, Elena; Verges, Dolors

    2014-01-01

    El envejecimiento satisfactorio como estado óptimo de un proceso de adaptación es poco conocido en las personas más mayores. Objetivo: Describir envejecimiento satisfactorio y analizar su asociación con indicadores de fragilidad en personas de 86 años. Diseño: Estudio descriptivo transversal al segundo año de seguimiento de un ensayo clínico (estudio Octabaix). Emplazamiento: Siete centros de atención primaria. Participantes: Personas nacidas en 1924, no institucionalizadas. Me...

  10. Perfil clínico del adulto mayor atendido ambulatoriamente en un hospital general.

    OpenAIRE

    Casas, Paola; Varela, Luis; Tello, Tania; Ortiz, Pedro; Chávez, Helver

    2012-01-01

    Objetivo: Describir el perfil clínico del adulto mayor atendido ambulatoriamente en un hospital general. Material y métodos: Estudio descriptivo, transversal, realizado a través de encuestas aplicadas a pacientes en la consulta ambulatoria de geriatría del Hospital Nacional Cayetano Heredia (HNCH), entre agosto de 2011 y enero 2012. Resultados: Se evaluaron 290 pacientes, el 69,3% fueron mujeres; el 65,5% tenía entre 60 y 79 años. La hipertensión arterial fue el diagnóstico más frecuente (55,...

  11. Valoración funcional del adulto mayor relacionado con el abandono familiar.

    OpenAIRE

    Jenny Fernanda Villarroel Vargas; Vicente Hernán Cárdenas Naranjo; Josefa Margarita Miranda Vázquez

    2017-01-01

    Introducción: Se estima que entre el 2000 al 2050 la población mundial envejecida ascenderá del 11% al 22 %, con ello el incremento de las diversas enfermedades o trastornos propios de la edad. Objetivo: Establecer la relación entre capacidad funcional del adulto mayor con el abandono familiar en el barrio La Calera Centro, Latacunga, 2015-2016. Métodos: Se realizó un estudio observacional descriptivo de corte trasversal, donde previo consentimiento informado participaron 70 adultos m...

  12. Niveles de bienestar espiritual y de fortaleza relacionados con la salud en adultos mayores

    OpenAIRE

    Martha V. Whetsell; Keville Frederickson; Paulina Aguilera; Juan Luis Maya

    2005-01-01

    Este estudio investigó la relación entre niveles de bienestar espiritual y fortaleza relacionada con la salud en una población mexicana de adultos mayores de 65 años. El proyecto se basó en el Modelo de Adaptación de Roy, el Modelo de Pollock (fortaleza relacionada con la salud) y el de Reed (bienestar espiritual). El diseño fue descriptivo correlacional, la muestra fue probabilística y se hizo al azar. La muestra (n=160) tuvo un nivel de significancia de 0,05 para una di...

  13. Revisión estructurada de las escalas de depresión en personas mayores

    OpenAIRE

    María José Cabañero-Martínez; Julio abrero-García; Miguel Richart-Martínez; Carmen Luz Muñoz-Mendoza; Abilio Reig-Ferrer

    2007-01-01

    El objetivo de este estudio teórico fue evaluar la adecuación conceptual, la aplicabilidad y las propiedades métricas de las medidas de depresión empleadas en la investigación con muestras de personas mayores españolas. Para ello se realizaron búsquedas electrónicas en las bases de datos nacionales IME e ISOC, y en las bases de datos internacionales MEDLINE, PsyInfo, CINAHL y Embase, así como búsquedas manuales en revistas reputadas del campo de la geriatría y la evaluación de ...

  14. Síndrome del cuidador de adultos mayores discapacitados y sus implicaciones psicosociales

    OpenAIRE

    Eliana Dueñas; María Anggeline Martínez; Benjamín Morales; Claudia Muñoz; Ana Sofía Viáfara; Julián A. Herrera

    2006-01-01

    Objetivo: Describir la prevalencia del síndrome del cuidador y las características psicosociales de los cuidadores de adultos mayores discapacitados. Materiales y métodos: Se realizó un estudio piloto de casos y controles en el Valle del Cauca durante el 2003-2004 para evaluar la funcionalidad familiar (APGAR familiar), la ansiedad y depresión (escala de Goldberg), la presencia de enfermedades (cuidadores y no cuidadores), y la prevalencia del síndrome del cuidador (escala de Zarit). Resul...

  15. Síndrome del cuidador de adultos mayores discapacitados y sus implicaciones psicosociales

    OpenAIRE

    Dueñas, Eliana; Martínez, María Anggeline; Morales, Benjamín; Muñoz, Claudia; Viáfara, Ana Sofía; Herrera, Julián A

    2006-01-01

    Objetivo: Describir la prevalencia del síndrome del cuidador y las características psicosociales de los cuidadores de adultos mayores discapacitados. Materiales y métodos: Se realizó un estudio piloto de casos y controles en el Valle del Cauca durante el 2003-2004 para evaluar la funcionalidad familiar (APGAR familiar), la ansiedad y depresión (escala de Goldberg), la presencia de enfermedades (cuidadores y no cuidadores), y la prevalencia del síndrome del cuidador (escala de Zarit). Resultad...

  16. Una lectura de los arcanos mayores desde la caverna platónica

    OpenAIRE

    Arango Agudelo, Alejandro

    2015-01-01

    El presente texto es una experiencia ensayística sobre la reflexión del símbolo, producto de la dialéctica entre la realidad epistémica y las claves del psicoanálisis propuesto por Jung. Desde este encuentro se iluminan algunas interpretaciones de las figuras arquetípicas presentes en los arcanos mayores del Tarot. Está redactado en primera persona del singular y del plural, estructurando un diálogo vitalista entre las percepciones del yo y el inconsciente colectivo.

  17. Fragilidad en el adulto mayor: Un primer acercamiento Frailty in the older adult: A first appraoch

    Directory of Open Access Journals (Sweden)

    Guido Emilio Lluis Ramos

    2004-08-01

    Full Text Available El estado de fragilidad es un síndrome clínico-biológico caracterizado por una disminución de la resistencia y de las reservas fisiológicas del adulto mayor ante situaciones estresantes, a consecuencia del acumulativo desgaste de los sistemas fisiológicos, causando mayor riesgo de sufrir efectos adversos para la salud como: caídas, discapacidad, hospitalización, institucionalización y muerte. La prevalencia reportada oscila entre un 7 y un 12 % en la población mayor de 65 años. La mayoría de los autores coinciden en que las manifestaciones clínicas más comunes son una disminución involuntaria del peso corporal, de la resistencia y de la fuerza muscular, trastornos del equilibrio y de la marcha y una declinación de la movilidad física. Varios estudios han relacionado el síndrome de fragilidad con biomarcadores y reactantes de fase aguda, inflamación, metabolismo y coagulación, en particular: proteína C reactiva, altos niveles del factor VIII de coagulación y fibrinógeno, insulina, glicemia, lípidos y proteínas como la albúmina.The frailty state is a clinical and biological syndrome characterized by a reduction of resistance and of the biological reserves of the older adult to stressing situations as a result of the accumulative waste of the physiological systems, causing higher risk for suffering adverse effects for health, such as. falls, disability, hospitalization, institutionalization and death. The reported prevalence ranged between 7 and 12 % in the population over 65. Most of the authors agree that the most common clinical manifestations are involuntary reduction of body weight, of resistance and of muscle strength, balance and walking disorders and a decrease of physical mobility. Many studies have related the frailty syndrome to biomarkers and reactants of acute stage, inflammation, metabolism and coagulation, in particular: reactive protein C, high levels of coagulation factor VIII and fibrinogen, insulin

  18. ACTIVIDAD FÍSICA EN UN GRUPO DE ADULTOS MAYORES QUE ACUDEN A CENTROS COMUNITARIOS

    OpenAIRE

    Abril Merizalde, Dennys Leonardo; Andrade Trujillo, Catherine Alexandra

    2017-01-01

    La esperanza de vida ha tenido un notable incremento en la actualidad y con ello el aumento de la prevalencia e incidencia de enfermedades como: diabetes tipo 2, enfermedades cardiovasculares, cerebrovasculares y pulmonares. De esta manera el adulto mayor es susceptible al deterioro de su estado nutricional y por lo tanto a una disminución de su funcionalidad e independencia lo que afecta directamente a su calidad de vida. El objetivo del presente estudio es realizar un análisis cuantitativo ...

  19. Caries Radicular en el Adulto Mayor. Revisión Narrativa de Literatura

    Directory of Open Access Journals (Sweden)

    Alberto Carlos Cruz-Gonzáles

    2015-07-01

    Full Text Available La caries radicular (CR se define como una lesión progresiva, crónica, con tejido reblandecido y originada en las raíces dentales expuestas al medio oral. Los adultos mayores son más susceptibles a presentar esta patología que otros grupos etarios, dada su mayor prevalencia de recesiones gingivales. El objetivo del presente artículo es realizar una revisión narrativa de la literatura sobre la caries radicular en el adulto mayor, con el fin de presentar una puesta al día que sirva de guía a los odontólogos para la toma de decisiones clínicas sobre su manejo. Se realizó una búsqueda de artículos en inglés y español, mediante los términos MESH Root Caries (AND Elderly en las bases de datos Pubmed, ScienceDirect, Google Scholar y Scielo, sin restricción para año de publicación. Se incluyeron artículos de investigación en seres humanos y revisiones sistemáticas sobre el tema. Inicialmente se obtuvieron 127 publicaciones de las que se descartaron 13 documentos, luego de la lectura de los resúmenes. Se encontró una alta prevalencia de CR en Colombia y en América Latina (27.6% y 23.71% respectivamente. Entre los factores de riesgo asociados, se reportaron la conservación de un mayor número de dientes en edades avanzadas, la recesión gingival, el acúmulo de biofilm, el uso de prótesis, la ingesta frecuente de azúcares refinados y las alteraciones físicas y cognoscitivas. Se encontró, igualmente, que la localización, el color, la textura superficial y la profundidad de la cavidad son factores determinantes del diagnóstico y el tratamiento de la CR y que la determinación del enfoque terapéutico parte de la clasificación del paciente en un nivel de riesgo.

  20. Personas mayores y sexualidad creativa. El derecho al placer a lo largo de la vida

    OpenAIRE

    Pérez Salanova, Mercè

    2016-01-01

    En este artículo se aborda la sexualidad y afectividad de las personas mayores. Partimos de la relevancia de la diversidad y de las experiencias subjetivas a lo largo del envejecimiento y proponemos una reflexión sobre las pérdidas y el trabajo de duelo marcados por una visión estereotipada de las prácticas sexuales centradas en la genitalidad y en el coito. También nos acercamos a los espacios de sociabilidad como lugares propicios para la comunicación y la muestra de afectos. Por último, no...

  1. Los procedimientos contables de Casa Boris: especial referencia al libro mayor (1872-1886)

    OpenAIRE

    José Paulo Cosenza; Carlos Antonio De Rocchi; Carlos Alberto Campello Ribeiro

    2014-01-01

    Boris Frères & Ltd. Co. (conocida popularmente como Casa Boris, denominación que se utiliza en este trabajo), durante ciento doce años tuvo un papel destacado en la economía de Ceará, una Provincia situada al Nordeste de Brasil. Este artículo examina los registros contables realizados en el Libro Mayor de la Casa Boris entre 1872 y 1886. El objetivo de este estudio es el de dar a conocer los hechos observados en el análisis del contenido de sus registros contables, con el fin de describir las...

  2. Autopercepción de salud general y mortalidad en adultos mayores

    Directory of Open Access Journals (Sweden)

    Ximena Moreno

    2014-05-01

    Conclusiones: Los resultados apoyan los hallazgos previos respecto a que la autopercepción de la salud general negativa predice la mortalidad. Es necesario dilucidar los mecanismos por los que este indicador puede predecir la mortalidad en los adultos mayores, que pueden ser diferentes para hombres y mujeres. Se sugiere investigar el papel de la depresión, considerando que el efecto de la autopercepción de la salud sobre la mortalidad no estaba presente en los estudios que la incluían.

  3. Hipnosis como complemento en la cirugía oral del adulto mayor

    Directory of Open Access Journals (Sweden)

    Elina Muñiz Manzano

    2013-03-01

    Full Text Available Introducción: el envejecimiento poblacional es un fenómeno mundial y la cirugía oral es compleja en los adultos mayores, por lo que la preparación preoperatoria es de vital importancia para una evolución satisfactoria. Este trabajo tiene como objetivo demostrar la eficacia de la hipnosis en pacientes con temor en la cirugía oral del adulto mayor. Métodos: se realizó un estudio descriptivo, transversal, con muestra de 20 pacientes de 60 años o más, atendidos en la consulta de Cirugía Maxilofacial del Hospital Universitario "Comandante Manuel Fajardo", en el año 2011, donde se analizaron las variables edad, sexo, número de sesiones de hipnosis, antecedentes patológicos, diagnósticos más frecuentes y temor. Resultados: el mayor número de pacientes se encontró entre 60-69 años de edad, (70 % y el menor en 70-79, (30 %. El sexo femenino prevaleció con 70 %. El número de sesiones fue en el grupo de 60-69 con 58, con un promedio total de 4 por pacientes. En los antecedentes patológicos más frecuentes fue la hipertensión arterial en 14 (70 % y le siguió la diabetes tipo II en 2 (10 % En los diagnósticos más frecuentes fue la caries de cuarto grado con 10 (50 % seguido por los dientes parodontósicos con 4 (20 %. El temor se midió en una escala confeccionada, en la que los pacientes con cifras de l0, 8 y 7 se redujeron a 4 y 5. Conclusiones: Se demuestra la efectividad de la terapia de hipnosis para disminuir el temor y realizar la cirugía oral en el adulto mayor.

  4. Nanotecnología : ¿beneficios para todos o mayor desigualdad?

    OpenAIRE

    Foladori, Guillermo; Invernizzi, Noelia

    2005-01-01

    Foladori, G., Invernizzi, N. (2005). Nanotecnología: ¿beneficios para todos o mayor desigualdad? Redes, 11(21), 55-75. La nanotecnología promete ser la próxima revolución tecnológica. El mercado de nanopartículas es reducido actualmente, pero se espera que en la próxima década se incremente considerablemente. Aunque es frecuentemente presentada como una tecnología limpia y ampliamente benéfica, la nanotecnología ya está generando considerable debate. Rápidamente han emergido controversias ...

  5. El desarrollo de la competencia mediática en personas mayores : una brecha pendiente

    OpenAIRE

    Hernando Gómez, Ángel; Phillippi, Alejandra

    2013-01-01

    El actual desarrollo de la sociedad de la información trajo consigo el fenómeno de las brechas por superar, en cuanto las posibles estrategias que han sido diseñadas por las distintas instancias gubernamentales para que las personas en general, puedan participar de los beneficios que reporta el actual paradigma de desarrollo. Las personas mayores corresponden a un grupo etario cuyo exponencial incremento poblacional supone un desafío para los diseñadores de políticas públicas. ...

  6. Intervención educativa en adultos mayores con diabetes mellitus en Guatemala

    OpenAIRE

    José Manuel Contreras Tejeda; Arely Díaz Cifuentes; Mayda Díaz Pérez; Aurora Seara Cifuentes

    2014-01-01

    Se realizó un estudio de intervención comunitaria, con el objetivo de incrementar los conocimientos en pacientes diabéticos adultos mayores, pertenecientes al Departamento Alta Verapaz, Cobán, Guatemala; en el período comprendido desde junio de 2011 hasta junio de 2012. El universo de estudio estuvo constituido por los pacientes diabéticos dispensarizados por el médico y la enfermera en el área periférica, conformándose la muestra con 46 de ellos, a los cuales se les evaluó el grado de conoci...

  7. Aprendizaje creativo en personas adultas mayores: la experiencia del Taller Literario del PAIPAM

    OpenAIRE

    Sancho Ugalde, María de los Ángeles

    2011-01-01

    El Taller Literario forma parte de las actividades del Programa de Atención Integral de la Persona Adulta Mayor (PAIPAM) del Centro de Estudios Generales de la Universidad Nacional de Costa Rica. Inició las sesiones de clase en febrero del 2007, en el género lírico; para el año 2008, en cuento; en el 2009, 2010 y 2011 ha sido desarrollado en narrativa. El propósito del taller es ofrecer espacios para el análisis de textos representativos de la literatura universal, latinoamericana y costarric...

  8. Unregulated Series Resonant Converter for Interlinking DC Nanogrids

    DEFF Research Database (Denmark)

    Tomas Manez, Kevin; Zhang, Zhe; Ouyang, Ziwei

    2017-01-01

    bidirectional converter to interlink a 400V DC bus with a 48V DC bus ispresented. The proposed converter is based on a LLC resonant converter operating as a DC transformer at a fixed frequency and duty cycle without any complex control strategy. A clearand simplified design procedure for high efficiency...

  9. Controller design and stability analysis of grid connected DC microgrid

    DEFF Research Database (Denmark)

    Chauhan, Rajeev Kumar; Chauhan, Kalpana; Guerrero, Josep M.

    2018-01-01

    DC microgrids are desired to provide the electricity for the remote areas which are far from the main grid. The microgrid gets popularity because DC power sources such as photovoltaics (PVs), battery banks, and fuel cells can be interconnected without AC/DC converters. The stochastic nature of PV...

  10. Active superconducting DC fault current limiter based on flux compensation

    International Nuclear Information System (INIS)

    Shi Jing; Tang Yuejin; Wang, Chen; Zhou Yusheng; Li Jingdong; Ren Li; Chen Shijie

    2006-01-01

    With the extensive application of DC power systems, suppression of DC fault current is an important subject that guarantees system security. This paper presents an active superconducting DC fault current limiter (DC-SFCL) based on flux compensation. The DC-SFCL is composed of two superconducting windings wound on a single iron core, the primary winding is in series with DC power system, and the second winding is connected with AC power system through a PWM converter. In normal operating state, the flux in the iron core is compensated to zero, and the SFCL has no influence on DC power system. In the case of DC system accident, through regulating the active power exchange between the SFCL's second winding and the AC power system, the current on the DC side can be limited to different level complying with the system demand. Moreover, the PWM converter that interface the DC system and AC system can be controlled as a reactive power source to supply voltage support for the AC side, which has little influence on the performance of SFCL. Using MATLAB SIMULINK, the mathematic model of the DC-SFCL is created, simulation results validate the dynamics of system, and the performance of DC-SFCL is confirmed

  11. Overvoltage protection in DC power systems; Ueberspannungsschutz in Gleichstromanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Birkl, Josef; Zahlmann, Peter [Dehn + Soehne GmbH + Co.KG, Neumarkt (Germany)

    2012-02-15

    The utilisation of DC power systems has increased dramatically in the recent years. In addition to traditional DC applications such as in telecommunications and railway engineering a variety of DC applications arise due to a rapid spread of photovoltaic systems. Current projects for the e-mobility expand the scope of application.

  12. On the modelling of linear-assisted DC-DC voltage regulators for photovoltaic solar energy systems

    Science.gov (United States)

    Martínez-García, Herminio; García-Vílchez, Encarna

    2017-11-01

    This paper shows the modelling of linear-assisted or hybrid (linear & switching) DC/DC voltage regulators. In this kind of regulators, an auxiliary linear regulator is used, which objective is to cancel the ripple at the output voltage and provide fast responses for load variations. On the other hand, a switching DC/DC converter, connected in parallel with the linear regulator, allows to supply almost the whole output current demanded by the load. The objective of this topology is to take advantage of the suitable regulation characteristics that series linear voltage regulators have, but almost achieving the high efficiency that switching DC/DC converters provide. Linear-assisted DC/DC regulators are feedback systems with potential instability. Therefore, their modelling is mandatory in order to obtain design guidelines and assure stability of the implemented power supply system.

  13. First Implementation of a Two-Stage DC-DC Conversion Powering Scheme for the CMS Phase-2 Outer Tracker

    CERN Document Server

    Feld, Lutz Werner; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Pauls, Alexander Josef; Preuten, Marius; Rauch, Max Philip; Wangelik, Frederik; Wlochal, Michael

    2017-01-01

    The 2S silicon strip modules for the CMS Phase-2 tracker upgrade will require two operating voltages. These will be provided via a two-step DC-DC conversion powering scheme, in which one DC-DC converter delivers 2.5\\,V while the second DC-DC converter receives 2.5\\,V at its input and converts it to 1.2\\,V. The DC-DC converters will be mounted on a flex PCB, the service hybrid, together with an opto-electrical converter module (VTRx+) and a serializer (LP-GBT). The service hybrid will be mounted directly on the 2S module. A prototype service hybrid has been developed and its performance has been evaluated, including radiative and conductive noise emissions, and efficiency. In addition system tests with a prototype module have been performed. In this report the service hybrid will be described and the test results will be summarized.

  14. All Digital Switch-Mode DC/DC Converters with BIST Functionality for Harsh Space Environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Micro Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

  15. DC-Voltage Fluctuation Elimination Through a DC-Capacitor Current Control for DFIG Converters Under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Liu, Changjin; Xu, Dehong; Zhu, Nan

    2013-01-01

    Unbalanced grid voltage causes a large second-order harmonic current in the dc-link capacitors as well as dc-voltage fluctuation, which potentially will degrade the lifespan and reliability of the capacitors in voltage source converters. This paper proposes a novel dc-capacitor current control...... method for a grid-side converter (GSC) to eliminate the negative impact of unbalanced grid voltage on the dc-capacitors. In this method, a dc-capacitor current control loop, where a negative-sequence resonant controller is used to increase the loop gain, is added to the conventional GSC current control...... loop. The rejection capability to the unbalanced grid voltage and the stability of the proposed control system are discussed. The second-order harmonic current in the dc capacitor as well as dc-voltage fluctuation is very well eliminated. Hence, the dc capacitors will be more reliable under unbalanced...

  16. Next-Generation Shipboard DC Power System

    DEFF Research Database (Denmark)

    Jin, Zheming; Sulligoi, Giorgio; Cuzner, Rob

    2016-01-01

    sources (RES) are commonly recognized as the major driven force of the revolution, the outburst of customer electronics and new kinds of household electronics is also powering this change. In this context, dc power distribution technologies have made a comeback and keep gaining a commendable increase...... in research interests and industrial applications. In addition, the concept of flexible and smart distribution has also been proposed, which tends to exploit distributed generation and pack the distributed RESs and local electrical loads as an independent and self-sustainable entity, namely microgrid....... At present, the research of dc microgrid has investigated and developed a series of advanced methods in control, management and objective-oriented optimization, which would found the technical interface enabling the future applications in multiple industrial areas, such as smart buildings, electric vehicles...

  17. Artificial noise due to DC electric trains

    International Nuclear Information System (INIS)

    Senanayake, W.E.

    1987-08-01

    The current distribution in a DC railway and the resulting magnetic effects have been modelled using the parameters of the DC railway networks in Italy. The results show that the magnetic perturbations are substantially high in the vicinity of electrified railway lines. The order of magnitude of the induced field can be as significant as ∼ 40nT at a distance of ≅ 2km from the railway line indicating that geophysical techniques that employ natural magnetic anomalies can be badly effected, within this range. The magnetic effects rapidly decay with increasing distance, but the noise level could be significant even at a range of ∼ 10km. Also, these induced anomalies vary significantly with the conductivity of the ground. When the conductivity is high it is possible that the railway currents dispersed through the ground interact with those induced in the earth, causing a severe disruption to the telluric measurements. (author). 11 refs, 10 figs, 1 tab

  18. Macroscopic quantum tunneling in a dc SQUID

    International Nuclear Information System (INIS)

    Chen, Y.C.

    1986-01-01

    The theory of macroscopic quantum tunneling is applied to a current-biased dc SQUID whose dynamics can be described by a two-dimensional mechanical system with a dissipative environment. Based on the phenomenological model proposed by Caldeira and Leggett, the dissipative environment is represented by a set of harmonic oscillators coupling to the system. After integrating out the environmental degrees of freedom, an effective Euclidean action is found for the two-dimensional system. The action is used to provide the quantum tunneling rate formalism for the dc SQUID. Under certain conditions, the tunneling rate reduces to that of a single current-biased Josephson junction with an adjustable effective critical current

  19. Universality of DC electrical conductivity from holography

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Xian-Hui, E-mail: gexh@shu.edu.cn [Shanghai Key Laboratory of High Temperature Superconductors, Department of Physics, Shanghai University, Shanghai, 200444 (China); Department of Physics, University of California, San Diego, CA92122 (United States); Sin, Sang-Jin, E-mail: sjsin@hangyang.ac.kr [Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Wu, Shao-Feng, E-mail: sfwu@shu.edu.cn [Department of Physics, Shanghai University, Shanghai, 200444 (China)

    2017-04-10

    We propose a universal formula of dc electrical conductivity in rotational- and translational-symmetries breaking systems via the holographic duality. This formula states that the ratio of the determinant of the dc electrical conductivities along any spatial directions to the black hole area density in zero-charge limit has a universal value. As explicit illustrations, we give several examples elucidating the validation of this formula: We construct an anisotropic black brane solution, which yields linear in temperature for the in-plane resistivity and insulating behavior for the out-of-plane resistivity; We also construct a spatially isotropic black brane solution that both the linear-T and quadratic-T contributions to the resistivity can be realized.

  20. A comprehensive analysis and hardware implementation of control strategies for high output voltage DC-DC boost power converter

    OpenAIRE

    Padmanaban, Sanjeevikumar; Grandi, Gabriele; Blaabjerg, Frede; Wheeler, Patrick; Siano, Pierluigi; Hammami, Manel

    2017-01-01

    Classical DC-DC converters used in high voltage direct current (HVDC) power transmission systems, lack in terms of efficiency, reduced transfer gain and increased cost with sensor (voltage/current) numbers. Besides, the internal self-parasitic behavior of the power components reduces the output voltage and efficiency of classical HV converters. This paper deals with extra high-voltage (EHV) dc-dc boost converter by the application of voltage-lift technique to overcome the aforementioned defic...